Merge branch 'master' into authenticationdb-efcore

# Conflicts:
#	Emby.Server.Implementations/Devices/DeviceManager.cs
#	Emby.Server.Implementations/HttpServer/Security/SessionContext.cs
#	Emby.Server.Implementations/Security/AuthenticationRepository.cs
#	Emby.Server.Implementations/Session/SessionManager.cs
#	Jellyfin.Server.Implementations/Security/AuthorizationContext.cs
#	MediaBrowser.Controller/Library/IUserManager.cs
#	MediaBrowser.Controller/Net/ISessionContext.cs

145 files changed, 983 insertions, 650 deletions

diff --git a/Emby.Server.Implementations/AppBase/BaseApplicationPaths.cs b/Emby.Server.Implementations/AppBase/BaseApplicationPaths.cs
index 660bbb2de..6edfad575 100644
--- a/Emby.Server.Implementations/AppBase/BaseApplicationPaths.cs
+++ b/Emby.Server.Implementations/AppBase/BaseApplicationPaths.cs
@@ -33,7 +33,7 @@ namespace Emby.Server.Implementations.AppBase
             CachePath = cacheDirectoryPath;
             WebPath = webDirectoryPath;
 
-            DataPath = Path.Combine(ProgramDataPath, "data");
+            _dataPath = Directory.CreateDirectory(Path.Combine(ProgramDataPath, "data")).FullName;
         }
 
         /// <summary>
@@ -55,11 +55,7 @@ namespace Emby.Server.Implementations.AppBase
         /// Gets the folder path to the data directory.
         /// </summary>
         /// <value>The data directory.</value>
-        public string DataPath
-        {
-            get => _dataPath;
-            private set => _dataPath = Directory.CreateDirectory(value).FullName;
-        }
+        public string DataPath => _dataPath;
 
         /// <inheritdoc />
         public string VirtualDataPath => "%AppDataPath%";
diff --git a/Emby.Server.Implementations/AppBase/BaseConfigurationManager.cs b/Emby.Server.Implementations/AppBase/BaseConfigurationManager.cs
index 4f72c8ce1..d38535634 100644
--- a/Emby.Server.Implementations/AppBase/BaseConfigurationManager.cs
+++ b/Emby.Server.Implementations/AppBase/BaseConfigurationManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -23,6 +25,11 @@ namespace Emby.Server.Implementations.AppBase
 
         private readonly ConcurrentDictionary<string, object> _configurations = new ConcurrentDictionary<string, object>();
 
+        /// <summary>
+        /// The _configuration sync lock.
+        /// </summary>
+        private readonly object _configurationSyncLock = new object();
+
         private ConfigurationStore[] _configurationStores = Array.Empty<ConfigurationStore>();
         private IConfigurationFactory[] _configurationFactories = Array.Empty<IConfigurationFactory>();
 
@@ -32,11 +39,6 @@ namespace Emby.Server.Implementations.AppBase
         private bool _configurationLoaded;
 
         /// <summary>
-        /// The _configuration sync lock.
-        /// </summary>
-        private readonly object _configurationSyncLock = new object();
-
-        /// <summary>
         /// The _configuration.
         /// </summary>
         private BaseApplicationConfiguration _configuration;
@@ -297,25 +299,29 @@ namespace Emby.Server.Implementations.AppBase
         /// <inheritdoc />
         public object GetConfiguration(string key)
         {
-            return _configurations.GetOrAdd(key, k =>
-            {
-                var file = GetConfigurationFile(key);
+            return _configurations.GetOrAdd(
+                key,
+                (k, configurationManager) =>
+                {
+                    var file = configurationManager.GetConfigurationFile(k);
 
-                var configurationInfo = _configurationStores
-                    .FirstOrDefault(i => string.Equals(i.Key, key, StringComparison.OrdinalIgnoreCase));
+                    var configurationInfo = Array.Find(
+                        configurationManager._configurationStores,
+                        i => string.Equals(i.Key, k, StringComparison.OrdinalIgnoreCase));
 
-                if (configurationInfo == null)
-                {
-                    throw new ResourceNotFoundException("Configuration with key " + key + " not found.");
-                }
+                    if (configurationInfo == null)
+                    {
+                        throw new ResourceNotFoundException("Configuration with key " + k + " not found.");
+                    }
 
-                var configurationType = configurationInfo.ConfigurationType;
+                    var configurationType = configurationInfo.ConfigurationType;
 
-                lock (_configurationSyncLock)
-                {
-                    return LoadConfiguration(file, configurationType);
-                }
-            });
+                    lock (configurationManager._configurationSyncLock)
+                    {
+                        return configurationManager.LoadConfiguration(file, configurationType);
+                    }
+                },
+                this);
         }
 
         private object LoadConfiguration(string path, Type configurationType)
diff --git a/Emby.Server.Implementations/AppBase/ConfigurationHelper.cs b/Emby.Server.Implementations/AppBase/ConfigurationHelper.cs
index 29bac6634..0308a68e4 100644
--- a/Emby.Server.Implementations/AppBase/ConfigurationHelper.cs
+++ b/Emby.Server.Implementations/AppBase/ConfigurationHelper.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.IO;
 using System.Linq;
@@ -35,7 +33,8 @@ namespace Emby.Server.Implementations.AppBase
             }
             catch (Exception)
             {
-                configuration = Activator.CreateInstance(type) ?? throw new ArgumentException($"Provided path ({type}) is not valid.", nameof(type));
+                // Note: CreateInstance returns null for Nullable<T>, e.g. CreateInstance(typeof(int?)) returns null.
+                configuration = Activator.CreateInstance(type)!;
             }
 
             using var stream = new MemoryStream(buffer?.Length ?? 0);
diff --git a/Emby.Server.Implementations/ApplicationHost.cs b/Emby.Server.Implementations/ApplicationHost.cs
index a69c4d035..baf5f88fc 100644
--- a/Emby.Server.Implementations/ApplicationHost.cs
+++ b/Emby.Server.Implementations/ApplicationHost.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Channels/ChannelManager.cs b/Emby.Server.Implementations/Channels/ChannelManager.cs
index 7324b0ee9..448f12403 100644
--- a/Emby.Server.Implementations/Channels/ChannelManager.cs
+++ b/Emby.Server.Implementations/Channels/ChannelManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Globalization;
diff --git a/Emby.Server.Implementations/Collections/CollectionImageProvider.cs b/Emby.Server.Implementations/Collections/CollectionImageProvider.cs
index c69a07e83..ca8409402 100644
--- a/Emby.Server.Implementations/Collections/CollectionImageProvider.cs
+++ b/Emby.Server.Implementations/Collections/CollectionImageProvider.cs
@@ -82,9 +82,9 @@ namespace Emby.Server.Implementations.Collections
                     return null;
                 })
                 .Where(i => i != null)
-                .GroupBy(x => x.Id)
+                .GroupBy(x => x!.Id) // We removed the null values
                 .Select(x => x.First())
-                .ToList();
+                .ToList()!; // Again... the list doesn't contain any null values
         }
 
         /// <inheritdoc />
diff --git a/Emby.Server.Implementations/Collections/CollectionManager.cs b/Emby.Server.Implementations/Collections/CollectionManager.cs
index c56f33448..82d80fc83 100644
--- a/Emby.Server.Implementations/Collections/CollectionManager.cs
+++ b/Emby.Server.Implementations/Collections/CollectionManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.IO;
diff --git a/Emby.Server.Implementations/Configuration/ServerConfigurationManager.cs b/Emby.Server.Implementations/Configuration/ServerConfigurationManager.cs
index 7a8ed8c29..ff5602f24 100644
--- a/Emby.Server.Implementations/Configuration/ServerConfigurationManager.cs
+++ b/Emby.Server.Implementations/Configuration/ServerConfigurationManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Globalization;
 using System.IO;
diff --git a/Emby.Server.Implementations/Cryptography/CryptographyProvider.cs b/Emby.Server.Implementations/Cryptography/CryptographyProvider.cs
index 12a9e44e7..4a9b28085 100644
--- a/Emby.Server.Implementations/Cryptography/CryptographyProvider.cs
+++ b/Emby.Server.Implementations/Cryptography/CryptographyProvider.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Collections.Generic;
 using System.Security.Cryptography;
diff --git a/Emby.Server.Implementations/Data/BaseSqliteRepository.cs b/Emby.Server.Implementations/Data/BaseSqliteRepository.cs
index c331a6112..6f23a0888 100644
--- a/Emby.Server.Implementations/Data/BaseSqliteRepository.cs
+++ b/Emby.Server.Implementations/Data/BaseSqliteRepository.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Data/ManagedConnection.cs b/Emby.Server.Implementations/Data/ManagedConnection.cs
index 5c094ddd2..afc8966f9 100644
--- a/Emby.Server.Implementations/Data/ManagedConnection.cs
+++ b/Emby.Server.Implementations/Data/ManagedConnection.cs
@@ -9,7 +9,7 @@ namespace Emby.Server.Implementations.Data
 {
     public class ManagedConnection : IDisposable
     {
-        private SQLiteDatabaseConnection _db;
+        private SQLiteDatabaseConnection? _db;
         private readonly SemaphoreSlim _writeLock;
         private bool _disposed = false;
 
@@ -54,12 +54,12 @@ namespace Emby.Server.Implementations.Data
             return _db.RunInTransaction(action, mode);
         }
 
-        public IEnumerable<IReadOnlyList<IResultSetValue>> Query(string sql)
+        public IEnumerable<IReadOnlyList<ResultSetValue>> Query(string sql)
         {
             return _db.Query(sql);
         }
 
-        public IEnumerable<IReadOnlyList<IResultSetValue>> Query(string sql, params object[] values)
+        public IEnumerable<IReadOnlyList<ResultSetValue>> Query(string sql, params object[] values)
         {
             return _db.Query(sql, values);
         }
diff --git a/Emby.Server.Implementations/Data/SqliteExtensions.cs b/Emby.Server.Implementations/Data/SqliteExtensions.cs
index a8f3feb58..3289e7609 100644
--- a/Emby.Server.Implementations/Data/SqliteExtensions.cs
+++ b/Emby.Server.Implementations/Data/SqliteExtensions.cs
@@ -1,9 +1,9 @@
+#nullable disable
 #pragma warning disable CS1591
 
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using SQLitePCL.pretty;
 
@@ -65,7 +65,7 @@ namespace Emby.Server.Implementations.Data
             });
         }
 
-        public static Guid ReadGuidFromBlob(this IResultSetValue result)
+        public static Guid ReadGuidFromBlob(this ResultSetValue result)
         {
             return new Guid(result.ToBlob());
         }
@@ -86,7 +86,7 @@ namespace Emby.Server.Implementations.Data
         private static string GetDateTimeKindFormat(DateTimeKind kind)
             => (kind == DateTimeKind.Utc) ? DatetimeFormatUtc : DatetimeFormatLocal;
 
-        public static DateTime ReadDateTime(this IResultSetValue result)
+        public static DateTime ReadDateTime(this ResultSetValue result)
         {
             var dateText = result.ToString();
 
@@ -97,7 +97,7 @@ namespace Emby.Server.Implementations.Data
                 DateTimeStyles.None).ToUniversalTime();
         }
 
-        public static bool TryReadDateTime(this IReadOnlyList<IResultSetValue> reader, int index, out DateTime result)
+        public static bool TryReadDateTime(this IReadOnlyList<ResultSetValue> reader, int index, out DateTime result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -118,7 +118,7 @@ namespace Emby.Server.Implementations.Data
             return false;
         }
 
-        public static bool TryGetGuid(this IReadOnlyList<IResultSetValue> reader, int index, out Guid result)
+        public static bool TryGetGuid(this IReadOnlyList<ResultSetValue> reader, int index, out Guid result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -131,17 +131,17 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool IsDbNull(this IResultSetValue result)
+        public static bool IsDbNull(this ResultSetValue result)
         {
             return result.SQLiteType == SQLiteType.Null;
         }
 
-        public static string GetString(this IReadOnlyList<IResultSetValue> result, int index)
+        public static string GetString(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ToString();
         }
 
-        public static bool TryGetString(this IReadOnlyList<IResultSetValue> reader, int index, out string result)
+        public static bool TryGetString(this IReadOnlyList<ResultSetValue> reader, int index, out string result)
         {
             result = null;
             var item = reader[index];
@@ -154,12 +154,12 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool GetBoolean(this IReadOnlyList<IResultSetValue> result, int index)
+        public static bool GetBoolean(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ToBool();
         }
 
-        public static bool TryGetBoolean(this IReadOnlyList<IResultSetValue> reader, int index, out bool result)
+        public static bool TryGetBoolean(this IReadOnlyList<ResultSetValue> reader, int index, out bool result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -172,7 +172,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool TryGetInt32(this IReadOnlyList<IResultSetValue> reader, int index, out int result)
+        public static bool TryGetInt32(this IReadOnlyList<ResultSetValue> reader, int index, out int result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -185,12 +185,12 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static long GetInt64(this IReadOnlyList<IResultSetValue> result, int index)
+        public static long GetInt64(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ToInt64();
         }
 
-        public static bool TryGetInt64(this IReadOnlyList<IResultSetValue> reader, int index, out long result)
+        public static bool TryGetInt64(this IReadOnlyList<ResultSetValue> reader, int index, out long result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -203,7 +203,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool TryGetSingle(this IReadOnlyList<IResultSetValue> reader, int index, out float result)
+        public static bool TryGetSingle(this IReadOnlyList<ResultSetValue> reader, int index, out float result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -216,7 +216,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static bool TryGetDouble(this IReadOnlyList<IResultSetValue> reader, int index, out double result)
+        public static bool TryGetDouble(this IReadOnlyList<ResultSetValue> reader, int index, out double result)
         {
             var item = reader[index];
             if (item.IsDbNull())
@@ -229,7 +229,7 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        public static Guid GetGuid(this IReadOnlyList<IResultSetValue> result, int index)
+        public static Guid GetGuid(this IReadOnlyList<ResultSetValue> result, int index)
         {
             return result[index].ReadGuidFromBlob();
         }
@@ -441,7 +441,7 @@ namespace Emby.Server.Implementations.Data
             }
         }
 
-        public static IEnumerable<IReadOnlyList<IResultSetValue>> ExecuteQuery(this IStatement statement)
+        public static IEnumerable<IReadOnlyList<ResultSetValue>> ExecuteQuery(this IStatement statement)
         {
             while (statement.MoveNext())
             {
diff --git a/Emby.Server.Implementations/Data/SqliteItemRepository.cs b/Emby.Server.Implementations/Data/SqliteItemRepository.cs
index b3d8860a9..9b147b5d7 100644
--- a/Emby.Server.Implementations/Data/SqliteItemRepository.cs
+++ b/Emby.Server.Implementations/Data/SqliteItemRepository.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -41,6 +43,7 @@ namespace Emby.Server.Implementations.Data
     /// </summary>
     public class SqliteItemRepository : BaseSqliteRepository, IItemRepository
     {
+        private const string FromText = " from TypedBaseItems A";
         private const string ChaptersTableName = "Chapters2";
 
         private readonly IServerConfigurationManager _config;
@@ -1043,18 +1046,34 @@ namespace Emby.Server.Implementations.Data
                 return Array.Empty<ItemImageInfo>();
             }
 
-            var list = new List<ItemImageInfo>();
-            foreach (var part in value.SpanSplit('|'))
+            // TODO The following is an ugly performance optimization, but it's extremely unlikely that the data in the database would be malformed
+            var valueSpan = value.AsSpan();
+            var count = valueSpan.Count('|') + 1;
+
+            var position = 0;
+            var result = new ItemImageInfo[count];
+            foreach (var part in valueSpan.Split('|'))
             {
                 var image = ItemImageInfoFromValueString(part);
 
                 if (image != null)
                 {
-                    list.Add(image);
+                    result[position++] = image;
                 }
             }
 
-            return list.ToArray();
+            if (position == count)
+            {
+                return result;
+            }
+
+            if (position == 0)
+            {
+                return Array.Empty<ItemImageInfo>();
+            }
+
+            // Extremely unlikely, but somehow one or more of the image strings were malformed. Cut the array.
+            return result[..position];
         }
 
         private void AppendItemImageInfo(StringBuilder bldr, ItemImageInfo image)
@@ -1282,12 +1301,12 @@ namespace Emby.Server.Implementations.Data
             return true;
         }
 
-        private BaseItem GetItem(IReadOnlyList<IResultSetValue> reader, InternalItemsQuery query)
+        private BaseItem GetItem(IReadOnlyList<ResultSetValue> reader, InternalItemsQuery query)
         {
             return GetItem(reader, query, HasProgramAttributes(query), HasEpisodeAttributes(query), HasServiceName(query), HasStartDate(query), HasTrailerTypes(query), HasArtistFields(query), HasSeriesFields(query));
         }
 
-        private BaseItem GetItem(IReadOnlyList<IResultSetValue> reader, InternalItemsQuery query, bool enableProgramAttributes, bool hasEpisodeAttributes, bool hasServiceName, bool queryHasStartDate, bool hasTrailerTypes, bool hasArtistFields, bool hasSeriesFields)
+        private BaseItem GetItem(IReadOnlyList<ResultSetValue> reader, InternalItemsQuery query, bool enableProgramAttributes, bool hasEpisodeAttributes, bool hasServiceName, bool queryHasStartDate, bool hasTrailerTypes, bool hasArtistFields, bool hasSeriesFields)
         {
             var typeString = reader.GetString(0);
 
@@ -1927,7 +1946,7 @@ namespace Emby.Server.Implementations.Data
         /// <param name="reader">The reader.</param>
         /// <param name="item">The item.</param>
         /// <returns>ChapterInfo.</returns>
-        private ChapterInfo GetChapter(IReadOnlyList<IResultSetValue> reader, BaseItem item)
+        private ChapterInfo GetChapter(IReadOnlyList<ResultSetValue> reader, BaseItem item)
         {
             var chapter = new ChapterInfo
             {
@@ -2248,10 +2267,8 @@ namespace Emby.Server.Implementations.Data
             return query.IncludeItemTypes.Any(x => _seriesTypes.Contains(x));
         }
 
-        private List<string> GetFinalColumnsToSelect(InternalItemsQuery query, IEnumerable<string> startColumns)
+        private void SetFinalColumnsToSelect(InternalItemsQuery query, List<string> columns)
         {
-            var list = startColumns.ToList();
-
             foreach (var field in _allFields)
             {
                 if (!HasField(query, field))
@@ -2259,28 +2276,28 @@ namespace Emby.Server.Implementations.Data
                     switch (field)
                     {
                         case ItemFields.Settings:
-                            list.Remove("IsLocked");
-                            list.Remove("PreferredMetadataCountryCode");
-                            list.Remove("PreferredMetadataLanguage");
-                            list.Remove("LockedFields");
+                            columns.Remove("IsLocked");
+                            columns.Remove("PreferredMetadataCountryCode");
+                            columns.Remove("PreferredMetadataLanguage");
+                            columns.Remove("LockedFields");
                             break;
                         case ItemFields.ServiceName:
-                            list.Remove("ExternalServiceId");
+                            columns.Remove("ExternalServiceId");
                             break;
                         case ItemFields.SortName:
-                            list.Remove("ForcedSortName");
+                            columns.Remove("ForcedSortName");
                             break;
                         case ItemFields.Taglines:
-                            list.Remove("Tagline");
+                            columns.Remove("Tagline");
                             break;
                         case ItemFields.Tags:
-                            list.Remove("Tags");
+                            columns.Remove("Tags");
                             break;
                         case ItemFields.IsHD:
                             // do nothing
                             break;
                         default:
-                            list.Remove(field.ToString());
+                            columns.Remove(field.ToString());
                             break;
                     }
                 }
@@ -2288,60 +2305,60 @@ namespace Emby.Server.Implementations.Data
 
             if (!HasProgramAttributes(query))
             {
-                list.Remove("IsMovie");
-                list.Remove("IsSeries");
-                list.Remove("EpisodeTitle");
-                list.Remove("IsRepeat");
-                list.Remove("ShowId");
+                columns.Remove("IsMovie");
+                columns.Remove("IsSeries");
+                columns.Remove("EpisodeTitle");
+                columns.Remove("IsRepeat");
+                columns.Remove("ShowId");
             }
 
             if (!HasEpisodeAttributes(query))
             {
-                list.Remove("SeasonName");
-                list.Remove("SeasonId");
+                columns.Remove("SeasonName");
+                columns.Remove("SeasonId");
             }
 
             if (!HasStartDate(query))
             {
-                list.Remove("StartDate");
+                columns.Remove("StartDate");
             }
 
             if (!HasTrailerTypes(query))
             {
-                list.Remove("TrailerTypes");
+                columns.Remove("TrailerTypes");
             }
 
             if (!HasArtistFields(query))
             {
-                list.Remove("AlbumArtists");
-                list.Remove("Artists");
+                columns.Remove("AlbumArtists");
+                columns.Remove("Artists");
             }
 
             if (!HasSeriesFields(query))
             {
-                list.Remove("SeriesId");
+                columns.Remove("SeriesId");
             }
 
             if (!HasEpisodeAttributes(query))
             {
-                list.Remove("SeasonName");
-                list.Remove("SeasonId");
+                columns.Remove("SeasonName");
+                columns.Remove("SeasonId");
             }
 
             if (!query.DtoOptions.EnableImages)
             {
-                list.Remove("Images");
+                columns.Remove("Images");
             }
 
             if (EnableJoinUserData(query))
             {
-                list.Add("UserDatas.UserId");
-                list.Add("UserDatas.lastPlayedDate");
-                list.Add("UserDatas.playbackPositionTicks");
-                list.Add("UserDatas.playcount");
-                list.Add("UserDatas.isFavorite");
-                list.Add("UserDatas.played");
-                list.Add("UserDatas.rating");
+                columns.Add("UserDatas.UserId");
+                columns.Add("UserDatas.lastPlayedDate");
+                columns.Add("UserDatas.playbackPositionTicks");
+                columns.Add("UserDatas.playcount");
+                columns.Add("UserDatas.isFavorite");
+                columns.Add("UserDatas.played");
+                columns.Add("UserDatas.rating");
             }
 
             if (query.SimilarTo != null)
@@ -2389,7 +2406,7 @@ namespace Emby.Server.Implementations.Data
 
                 builder.Append(") as SimilarityScore");
 
-                list.Add(builder.ToString());
+                columns.Add(builder.ToString());
 
                 var oldLen = query.ExcludeItemIds.Length;
                 var newLen = oldLen + item.ExtraIds.Length + 1;
@@ -2416,10 +2433,8 @@ namespace Emby.Server.Implementations.Data
 
                 builder.Append(") as SearchScore");
 
-                list.Add(builder.ToString());
+                columns.Add(builder.ToString());
             }
-
-            return list;
         }
 
         private void BindSearchParams(InternalItemsQuery query, IStatement statement)
@@ -2485,31 +2500,25 @@ namespace Emby.Server.Implementations.Data
 
         private string GetGroupBy(InternalItemsQuery query)
         {
-            var groups = new List<string>();
-
-            if (EnableGroupByPresentationUniqueKey(query))
+            var enableGroupByPresentationUniqueKey = EnableGroupByPresentationUniqueKey(query);
+            if (enableGroupByPresentationUniqueKey && query.GroupBySeriesPresentationUniqueKey)
             {
-                groups.Add("PresentationUniqueKey");
+                return " Group by PresentationUniqueKey, SeriesPresentationUniqueKey";
             }
 
-            if (query.GroupBySeriesPresentationUniqueKey)
+            if (enableGroupByPresentationUniqueKey)
             {
-                groups.Add("SeriesPresentationUniqueKey");
+                return " Group by PresentationUniqueKey";
             }
 
-            if (groups.Count > 0)
+            if (query.GroupBySeriesPresentationUniqueKey)
             {
-                return " Group by " + string.Join(',', groups);
+                return " Group by SeriesPresentationUniqueKey";
             }
 
             return string.Empty;
         }
 
-        private string GetFromText(string alias = "A")
-        {
-            return " from TypedBaseItems " + alias;
-        }
-
         public int GetCount(InternalItemsQuery query)
         {
             if (query == null)
@@ -2527,17 +2536,21 @@ namespace Emby.Server.Implementations.Data
                 query.Limit = query.Limit.Value + 4;
             }
 
-            var commandText = "select "
-                              + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count(distinct PresentationUniqueKey)" }))
-                              + GetFromText()
-                              + GetJoinUserDataText(query);
+            var columns = new List<string> { "count(distinct PresentationUniqueKey)" };
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 256)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
             if (whereClauses.Count != 0)
             {
-                commandText += " where " + string.Join(" AND ", whereClauses);
+                commandTextBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses);
             }
 
+            var commandText = commandTextBuilder.ToString();
             int count;
             using (var connection = GetConnection(true))
             {
@@ -2579,20 +2592,23 @@ namespace Emby.Server.Implementations.Data
                 query.Limit = query.Limit.Value + 4;
             }
 
-            var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, _retriveItemColumns))
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            var columns = _retriveItemColumns.ToList();
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 1024)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
 
             if (whereClauses.Count != 0)
             {
-                commandText += " where " + string.Join(" AND ", whereClauses);
+                commandTextBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses);
             }
 
-            commandText += GetGroupBy(query)
-                        + GetOrderByText(query);
+            commandTextBuilder.Append(GetGroupBy(query))
+                .Append(GetOrderByText(query));
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
             {
@@ -2600,15 +2616,18 @@ namespace Emby.Server.Implementations.Data
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
+            var commandText = commandTextBuilder.ToString();
             var items = new List<BaseItem>();
             using (var connection = GetConnection(true))
             {
@@ -2764,20 +2783,27 @@ namespace Emby.Server.Implementations.Data
                 query.Limit = query.Limit.Value + 4;
             }
 
-            var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, _retriveItemColumns))
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            var columns = _retriveItemColumns.ToList();
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 512)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
 
             var whereText = whereClauses.Count == 0 ?
                 string.Empty :
-                " where " + string.Join(" AND ", whereClauses);
+                string.Join(" AND ", whereClauses);
 
-            commandText += whereText
-                        + GetGroupBy(query)
-                        + GetOrderByText(query);
+            if (!string.IsNullOrEmpty(whereText))
+            {
+                commandTextBuilder.Append(" where ")
+                    .Append(whereText);
+            }
+
+            commandTextBuilder.Append(GetGroupBy(query))
+                .Append(GetOrderByText(query));
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
             {
@@ -2785,43 +2811,58 @@ namespace Emby.Server.Implementations.Data
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
             var isReturningZeroItems = query.Limit.HasValue && query.Limit <= 0;
 
-            var statementTexts = new List<string>();
+            var itemQuery = string.Empty;
+            var totalRecordCountQuery = string.Empty;
             if (!isReturningZeroItems)
             {
-                statementTexts.Add(commandText);
+                itemQuery = commandTextBuilder.ToString();
             }
 
             if (query.EnableTotalRecordCount)
             {
-                commandText = string.Empty;
+                commandTextBuilder.Clear();
+
+                commandTextBuilder.Append(" select ");
 
+                List<string> columnsToSelect;
                 if (EnableGroupByPresentationUniqueKey(query))
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct PresentationUniqueKey)" };
                 }
                 else if (query.GroupBySeriesPresentationUniqueKey)
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct SeriesPresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct SeriesPresentationUniqueKey)" };
                 }
                 else
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (guid)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (guid)" };
                 }
 
-                commandText += GetJoinUserDataText(query)
-                            + whereText;
-                statementTexts.Add(commandText);
+                SetFinalColumnsToSelect(query, columnsToSelect);
+
+                commandTextBuilder.AppendJoin(',', columnsToSelect)
+                    .Append(FromText)
+                    .Append(GetJoinUserDataText(query));
+                if (!string.IsNullOrEmpty(whereText))
+                {
+                    commandTextBuilder.Append(" where ")
+                        .Append(whereText);
+                }
+
+                totalRecordCountQuery = commandTextBuilder.ToString();
             }
 
             var list = new List<BaseItem>();
@@ -2831,11 +2872,12 @@ namespace Emby.Server.Implementations.Data
                 connection.RunInTransaction(
                 db =>
                 {
-                    var statements = PrepareAll(db, statementTexts);
+                    var itemQueryStatement = PrepareStatement(db, itemQuery);
+                    var totalRecordCountQueryStatement = PrepareStatement(db, totalRecordCountQuery);
 
                     if (!isReturningZeroItems)
                     {
-                        using (var statement = statements[0])
+                        using (var statement = itemQueryStatement)
                         {
                             if (EnableJoinUserData(query))
                             {
@@ -2865,11 +2907,14 @@ namespace Emby.Server.Implementations.Data
                                 }
                             }
                         }
+
+                        LogQueryTime("GetItems.ItemQuery", itemQuery, now);
                     }
 
+                    now = DateTime.UtcNow;
                     if (query.EnableTotalRecordCount)
                     {
-                        using (var statement = statements[statements.Length - 1])
+                        using (var statement = totalRecordCountQueryStatement)
                         {
                             if (EnableJoinUserData(query))
                             {
@@ -2884,11 +2929,12 @@ namespace Emby.Server.Implementations.Data
 
                             result.TotalRecordCount = statement.ExecuteQuery().SelectScalarInt().First();
                         }
+
+                        LogQueryTime("GetItems.TotalRecordCount", totalRecordCountQuery, now);
                     }
                 }, ReadTransactionMode);
             }
 
-            LogQueryTime("GetItems", commandText, now);
             result.Items = list;
             return result;
         }
@@ -3021,19 +3067,22 @@ namespace Emby.Server.Implementations.Data
 
             var now = DateTime.UtcNow;
 
-            var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, new[] { "guid" }))
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            var columns = new List<string> { "guid" };
+            SetFinalColumnsToSelect(query, columns);
+            var commandTextBuilder = new StringBuilder("select ", 256)
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query));
 
             var whereClauses = GetWhereClauses(query, null);
             if (whereClauses.Count != 0)
             {
-                commandText += " where " + string.Join(" AND ", whereClauses);
+                commandTextBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses);
             }
 
-            commandText += GetGroupBy(query)
-                        + GetOrderByText(query);
+            commandTextBuilder.Append(GetGroupBy(query))
+                .Append(GetOrderByText(query));
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
             {
@@ -3041,15 +3090,18 @@ namespace Emby.Server.Implementations.Data
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    commandTextBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
+            var commandText = commandTextBuilder.ToString();
             var list = new List<Guid>();
             using (var connection = GetConnection(true))
             {
@@ -3088,7 +3140,9 @@ namespace Emby.Server.Implementations.Data
 
             var now = DateTime.UtcNow;
 
-            var commandText = "select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "guid", "path" })) + GetFromText();
+            var columns = new List<string> { "guid", "path" };
+            SetFinalColumnsToSelect(query, columns);
+            var commandText = "select " + string.Join(',', columns) + FromText;
 
             var whereClauses = GetWhereClauses(query, null);
             if (whereClauses.Count != 0)
@@ -3164,9 +3218,11 @@ namespace Emby.Server.Implementations.Data
 
             var now = DateTime.UtcNow;
 
+            var columns = new List<string> { "guid" };
+            SetFinalColumnsToSelect(query, columns);
             var commandText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, new[] { "guid" }))
-                            + GetFromText()
+                            + string.Join(',', columns)
+                            + FromText
                             + GetJoinUserDataText(query);
 
             var whereClauses = GetWhereClauses(query, null);
@@ -3206,19 +3262,23 @@ namespace Emby.Server.Implementations.Data
             {
                 commandText = string.Empty;
 
+                List<string> columnsToSelect;
                 if (EnableGroupByPresentationUniqueKey(query))
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct PresentationUniqueKey)" };
                 }
                 else if (query.GroupBySeriesPresentationUniqueKey)
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct SeriesPresentationUniqueKey)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (distinct SeriesPresentationUniqueKey)" };
                 }
                 else
                 {
-                    commandText += " select " + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (guid)" })) + GetFromText();
+                    columnsToSelect = new List<string> { "count (guid)" };
                 }
 
+                SetFinalColumnsToSelect(query, columnsToSelect);
+                commandText += " select " + string.Join(',', columnsToSelect) + FromText;
+
                 commandText += GetJoinUserDataText(query)
                             + whereText;
                 statementTexts.Add(commandText);
@@ -4413,56 +4473,50 @@ namespace Emby.Server.Implementations.Data
                 whereClauses.Add(GetProviderIdClause(query.HasTvdbId.Value, "tvdb"));
             }
 
-            var includedItemByNameTypes = GetItemByNameTypesInQuery(query);
-            var enableItemsByName = (query.IncludeItemsByName ?? false) && includedItemByNameTypes.Count > 0;
-
             var queryTopParentIds = query.TopParentIds;
 
-            if (queryTopParentIds.Length == 1)
+            if (queryTopParentIds.Length > 0)
             {
-                if (enableItemsByName && includedItemByNameTypes.Count == 1)
+                var includedItemByNameTypes = GetItemByNameTypesInQuery(query);
+                var enableItemsByName = (query.IncludeItemsByName ?? false) && includedItemByNameTypes.Count > 0;
+
+                if (queryTopParentIds.Length == 1)
                 {
-                    whereClauses.Add("(TopParentId=@TopParentId or Type=@IncludedItemByNameType)");
-                    if (statement != null)
+                    if (enableItemsByName && includedItemByNameTypes.Count == 1)
                     {
-                        statement.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
+                        whereClauses.Add("(TopParentId=@TopParentId or Type=@IncludedItemByNameType)");
+                        statement?.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
+                    }
+                    else if (enableItemsByName && includedItemByNameTypes.Count > 1)
+                    {
+                        var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
+                        whereClauses.Add("(TopParentId=@TopParentId or Type in (" + itemByNameTypeVal + "))");
+                    }
+                    else
+                    {
+                        whereClauses.Add("(TopParentId=@TopParentId)");
                     }
-                }
-                else if (enableItemsByName && includedItemByNameTypes.Count > 1)
-                {
-                    var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
-                    whereClauses.Add("(TopParentId=@TopParentId or Type in (" + itemByNameTypeVal + "))");
-                }
-                else
-                {
-                    whereClauses.Add("(TopParentId=@TopParentId)");
-                }
 
-                if (statement != null)
-                {
-                    statement.TryBind("@TopParentId", queryTopParentIds[0].ToString("N", CultureInfo.InvariantCulture));
+                    statement?.TryBind("@TopParentId", queryTopParentIds[0].ToString("N", CultureInfo.InvariantCulture));
                 }
-            }
-            else if (queryTopParentIds.Length > 1)
-            {
-                var val = string.Join(',', queryTopParentIds.Select(i => "'" + i.ToString("N", CultureInfo.InvariantCulture) + "'"));
-
-                if (enableItemsByName && includedItemByNameTypes.Count == 1)
+                else if (queryTopParentIds.Length > 1)
                 {
-                    whereClauses.Add("(Type=@IncludedItemByNameType or TopParentId in (" + val + "))");
-                    if (statement != null)
+                    var val = string.Join(',', queryTopParentIds.Select(i => "'" + i.ToString("N", CultureInfo.InvariantCulture) + "'"));
+
+                    if (enableItemsByName && includedItemByNameTypes.Count == 1)
                     {
-                        statement.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
+                        whereClauses.Add("(Type=@IncludedItemByNameType or TopParentId in (" + val + "))");
+                        statement?.TryBind("@IncludedItemByNameType", includedItemByNameTypes[0]);
+                    }
+                    else if (enableItemsByName && includedItemByNameTypes.Count > 1)
+                    {
+                        var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
+                        whereClauses.Add("(Type in (" + itemByNameTypeVal + ") or TopParentId in (" + val + "))");
+                    }
+                    else
+                    {
+                        whereClauses.Add("TopParentId in (" + val + ")");
                     }
-                }
-                else if (enableItemsByName && includedItemByNameTypes.Count > 1)
-                {
-                    var itemByNameTypeVal = string.Join(',', includedItemByNameTypes.Select(i => "'" + i + "'"));
-                    whereClauses.Add("(Type in (" + itemByNameTypeVal + ") or TopParentId in (" + val + "))");
-                }
-                else
-                {
-                    whereClauses.Add("TopParentId in (" + val + ")");
                 }
             }
 
@@ -4744,17 +4798,12 @@ namespace Emby.Server.Implementations.Data
                 return true;
             }
 
-            var types = new[]
-            {
-                nameof(Episode),
-                nameof(Video),
-                nameof(Movie),
-                nameof(MusicVideo),
-                nameof(Series),
-                nameof(Season)
-            };
-
-            if (types.Any(i => query.IncludeItemTypes.Contains(i, StringComparer.OrdinalIgnoreCase)))
+            if (query.IncludeItemTypes.Contains(nameof(Episode), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Video), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Movie), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(MusicVideo), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Series), StringComparer.OrdinalIgnoreCase)
+                || query.IncludeItemTypes.Contains(nameof(Season), StringComparer.OrdinalIgnoreCase))
             {
                 return true;
             }
@@ -5198,37 +5247,45 @@ AND Type = @InternalPersonType)");
 
             var now = DateTime.UtcNow;
 
-            var typeClause = itemValueTypes.Length == 1 ?
-                ("Type=" + itemValueTypes[0].ToString(CultureInfo.InvariantCulture)) :
-                ("Type in (" + string.Join(',', itemValueTypes.Select(i => i.ToString(CultureInfo.InvariantCulture))) + ")");
-
-            var commandText = "Select Value From ItemValues where " + typeClause;
+            var stringBuilder = new StringBuilder("Select Value From ItemValues where Type", 128);
+            if (itemValueTypes.Length == 1)
+            {
+                stringBuilder.Append('=')
+                    .Append(itemValueTypes[0]);
+            }
+            else
+            {
+                stringBuilder.Append(" in (")
+                    .AppendJoin(',', itemValueTypes)
+                    .Append(')');
+            }
 
             if (withItemTypes.Count > 0)
             {
-                var typeString = string.Join(',', withItemTypes.Select(i => "'" + i + "'"));
-                commandText += " AND ItemId In (select guid from typedbaseitems where type in (" + typeString + "))";
+                stringBuilder.Append(" AND ItemId In (select guid from typedbaseitems where type in (")
+                    .AppendJoinInSingleQuotes(',', withItemTypes)
+                    .Append("))");
             }
 
             if (excludeItemTypes.Count > 0)
             {
-                var typeString = string.Join(',', excludeItemTypes.Select(i => "'" + i + "'"));
-                commandText += " AND ItemId not In (select guid from typedbaseitems where type in (" + typeString + "))";
+                stringBuilder.Append(" AND ItemId not In (select guid from typedbaseitems where type in (")
+                    .AppendJoinInSingleQuotes(',', excludeItemTypes)
+                    .Append("))");
             }
 
-            commandText += " Group By CleanValue";
+            stringBuilder.Append(" Group By CleanValue");
+            var commandText = stringBuilder.ToString();
 
             var list = new List<string>();
             using (var connection = GetConnection(true))
+            using (var statement = PrepareStatement(connection, commandText))
             {
-                using (var statement = PrepareStatement(connection, commandText))
+                foreach (var row in statement.ExecuteQuery())
                 {
-                    foreach (var row in statement.ExecuteQuery())
+                    if (row.TryGetString(0, out var result))
                     {
-                        if (row.TryGetString(0, out var result))
-                        {
-                            list.Add(result);
-                        }
+                        list.Add(result);
                     }
                 }
             }
@@ -5254,18 +5311,19 @@ AND Type = @InternalPersonType)");
             var now = DateTime.UtcNow;
 
             var typeClause = itemValueTypes.Length == 1 ?
-                ("Type=" + itemValueTypes[0].ToString(CultureInfo.InvariantCulture)) :
-                ("Type in (" + string.Join(',', itemValueTypes.Select(i => i.ToString(CultureInfo.InvariantCulture))) + ")");
+                ("Type=" + itemValueTypes[0]) :
+                ("Type in (" + string.Join(',', itemValueTypes) + ")");
 
             InternalItemsQuery typeSubQuery = null;
 
-            Dictionary<string, string> itemCountColumns = null;
+            string itemCountColumns = null;
 
+            var stringBuilder = new StringBuilder(1024);
             var typesToCount = query.IncludeItemTypes;
 
             if (typesToCount.Length > 0)
             {
-                var itemCountColumnQuery = "select group_concat(type, '|')" + GetFromText("B");
+                stringBuilder.Append("(select group_concat(type, '|') from TypedBaseItems B");
 
                 typeSubQuery = new InternalItemsQuery(query.User)
                 {
@@ -5281,20 +5339,22 @@ AND Type = @InternalPersonType)");
                 };
                 var whereClauses = GetWhereClauses(typeSubQuery, null);
 
-                whereClauses.Add("guid in (select ItemId from ItemValues where ItemValues.CleanValue=A.CleanName AND " + typeClause + ")");
+                stringBuilder.Append(" where ")
+                    .AppendJoin(" AND ", whereClauses)
+                    .Append(" AND ")
+                    .Append("guid in (select ItemId from ItemValues where ItemValues.CleanValue=A.CleanName AND ")
+                    .Append(typeClause)
+                    .Append(")) as itemTypes");
 
-                itemCountColumnQuery += " where " + string.Join(" AND ", whereClauses);
-
-                itemCountColumns = new Dictionary<string, string>()
-                {
-                    { "itemTypes", "(" + itemCountColumnQuery + ") as itemTypes" }
-                };
+                itemCountColumns = stringBuilder.ToString();
+                stringBuilder.Clear();
             }
 
             List<string> columns = _retriveItemColumns.ToList();
-            if (itemCountColumns != null)
+            // Unfortunately we need to add it to columns to ensure the order of the columns in the select
+            if (!string.IsNullOrEmpty(itemCountColumns))
             {
-                columns.AddRange(itemCountColumns.Values);
+                columns.Add(itemCountColumns);
             }
 
             // do this first before calling GetFinalColumnsToSelect, otherwise ExcludeItemIds will be set by SimilarTo
@@ -5315,20 +5375,20 @@ AND Type = @InternalPersonType)");
                 IsSeries = query.IsSeries
             };
 
-            columns = GetFinalColumnsToSelect(query, columns);
-
-            var commandText = "select "
-                            + string.Join(',', columns)
-                            + GetFromText()
-                            + GetJoinUserDataText(query);
+            SetFinalColumnsToSelect(query, columns);
 
             var innerWhereClauses = GetWhereClauses(innerQuery, null);
 
-            var innerWhereText = innerWhereClauses.Count == 0 ?
-                string.Empty :
-                " where " + string.Join(" AND ", innerWhereClauses);
+            stringBuilder.Append(" where Type=@SelectType And CleanName In (Select CleanValue from ItemValues where ")
+                .Append(typeClause)
+                .Append(" AND ItemId in (select guid from TypedBaseItems");
+            if (innerWhereClauses.Count > 0)
+            {
+                stringBuilder.Append(" where ")
+                    .AppendJoin(" AND ", innerWhereClauses);
+            }
 
-            var whereText = " where Type=@SelectType And CleanName In (Select CleanValue from ItemValues where " + typeClause + " AND ItemId in (select guid from TypedBaseItems" + innerWhereText + "))";
+            stringBuilder.Append("))");
 
             var outerQuery = new InternalItemsQuery(query.User)
             {
@@ -5353,23 +5413,31 @@ AND Type = @InternalPersonType)");
             };
 
             var outerWhereClauses = GetWhereClauses(outerQuery, null);
-
             if (outerWhereClauses.Count != 0)
             {
-                whereText += " AND " + string.Join(" AND ", outerWhereClauses);
+                stringBuilder.Append(" AND ")
+                    .AppendJoin(" AND ", outerWhereClauses);
             }
 
-            commandText += whereText + " group by PresentationUniqueKey";
+            var whereText = stringBuilder.ToString();
+            stringBuilder.Clear();
+
+            stringBuilder.Append("select ")
+                .AppendJoin(',', columns)
+                .Append(FromText)
+                .Append(GetJoinUserDataText(query))
+                .Append(whereText)
+                .Append(" group by PresentationUniqueKey");
 
             if (query.OrderBy.Count != 0
                 || query.SimilarTo != null
                 || !string.IsNullOrEmpty(query.SearchTerm))
             {
-                commandText += GetOrderByText(query);
+                stringBuilder.Append(GetOrderByText(query));
             }
             else
             {
-                commandText += " order by SortName";
+                stringBuilder.Append(" order by SortName");
             }
 
             if (query.Limit.HasValue || query.StartIndex.HasValue)
@@ -5378,32 +5446,39 @@ AND Type = @InternalPersonType)");
 
                 if (query.Limit.HasValue || offset > 0)
                 {
-                    commandText += " LIMIT " + (query.Limit ?? int.MaxValue).ToString(CultureInfo.InvariantCulture);
+                    stringBuilder.Append(" LIMIT ")
+                        .Append(query.Limit ?? int.MaxValue);
                 }
 
                 if (offset > 0)
                 {
-                    commandText += " OFFSET " + offset.ToString(CultureInfo.InvariantCulture);
+                    stringBuilder.Append(" OFFSET ")
+                        .Append(offset);
                 }
             }
 
             var isReturningZeroItems = query.Limit.HasValue && query.Limit <= 0;
 
-            var statementTexts = new List<string>();
+            string commandText = string.Empty;
+
             if (!isReturningZeroItems)
             {
-                statementTexts.Add(commandText);
+                commandText = stringBuilder.ToString();
             }
 
+            string countText = string.Empty;
             if (query.EnableTotalRecordCount)
             {
-                var countText = "select "
-                            + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" }))
-                            + GetFromText()
-                            + GetJoinUserDataText(query)
-                            + whereText;
+                stringBuilder.Clear();
+                var columnsToSelect = new List<string> { "count (distinct PresentationUniqueKey)" };
+                SetFinalColumnsToSelect(query, columnsToSelect);
+                stringBuilder.Append("select ")
+                    .AppendJoin(',', columnsToSelect)
+                    .Append(FromText)
+                    .Append(GetJoinUserDataText(query))
+                    .Append(whereText);
 
-                statementTexts.Add(countText);
+                countText = stringBuilder.ToString();
             }
 
             var list = new List<(BaseItem, ItemCounts)>();
@@ -5413,11 +5488,9 @@ AND Type = @InternalPersonType)");
                 connection.RunInTransaction(
                     db =>
                     {
-                        var statements = PrepareAll(db, statementTexts);
-
                         if (!isReturningZeroItems)
                         {
-                            using (var statement = statements[0])
+                            using (var statement = PrepareStatement(db, commandText))
                             {
                                 statement.TryBind("@SelectType", returnType);
                                 if (EnableJoinUserData(query))
@@ -5458,13 +5531,7 @@ AND Type = @InternalPersonType)");
 
                         if (query.EnableTotalRecordCount)
                         {
-                            commandText = "select "
-                                        + string.Join(',', GetFinalColumnsToSelect(query, new[] { "count (distinct PresentationUniqueKey)" }))
-                                        + GetFromText()
-                                        + GetJoinUserDataText(query)
-                                        + whereText;
-
-                            using (var statement = statements[statements.Length - 1])
+                            using (var statement = PrepareStatement(db, countText))
                             {
                                 statement.TryBind("@SelectType", returnType);
                                 if (EnableJoinUserData(query))
@@ -5501,7 +5568,7 @@ AND Type = @InternalPersonType)");
             return result;
         }
 
-        private static ItemCounts GetItemCounts(IReadOnlyList<IResultSetValue> reader, int countStartColumn, string[] typesToCount)
+        private static ItemCounts GetItemCounts(IReadOnlyList<ResultSetValue> reader, int countStartColumn, string[] typesToCount)
         {
             var counts = new ItemCounts();
 
@@ -5732,7 +5799,7 @@ AND Type = @InternalPersonType)");
             }
         }
 
-        private PersonInfo GetPerson(IReadOnlyList<IResultSetValue> reader)
+        private PersonInfo GetPerson(IReadOnlyList<ResultSetValue> reader)
         {
             var item = new PersonInfo
             {
@@ -5939,7 +6006,7 @@ AND Type = @InternalPersonType)");
         /// </summary>
         /// <param name="reader">The reader.</param>
         /// <returns>ChapterInfo.</returns>
-        private MediaStream GetMediaStream(IReadOnlyList<IResultSetValue> reader)
+        private MediaStream GetMediaStream(IReadOnlyList<ResultSetValue> reader)
         {
             var item = new MediaStream
             {
@@ -6240,7 +6307,7 @@ AND Type = @InternalPersonType)");
         /// </summary>
         /// <param name="reader">The reader.</param>
         /// <returns>MediaAttachment.</returns>
-        private MediaAttachment GetMediaAttachment(IReadOnlyList<IResultSetValue> reader)
+        private MediaAttachment GetMediaAttachment(IReadOnlyList<ResultSetValue> reader)
         {
             var item = new MediaAttachment
             {
diff --git a/Emby.Server.Implementations/Data/SqliteUserDataRepository.cs b/Emby.Server.Implementations/Data/SqliteUserDataRepository.cs
index e0ebd0a6c..ef9af1dcd 100644
--- a/Emby.Server.Implementations/Data/SqliteUserDataRepository.cs
+++ b/Emby.Server.Implementations/Data/SqliteUserDataRepository.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -348,7 +350,7 @@ namespace Emby.Server.Implementations.Data
         /// Read a row from the specified reader into the provided userData object.
         /// </summary>
         /// <param name="reader"></param>
-        private UserItemData ReadRow(IReadOnlyList<IResultSetValue> reader)
+        private UserItemData ReadRow(IReadOnlyList<ResultSetValue> reader)
         {
             var userData = new UserItemData();
 
diff --git a/Emby.Server.Implementations/Data/TypeMapper.cs b/Emby.Server.Implementations/Data/TypeMapper.cs
index 7044b1d19..064664e1f 100644
--- a/Emby.Server.Implementations/Data/TypeMapper.cs
+++ b/Emby.Server.Implementations/Data/TypeMapper.cs
@@ -13,7 +13,7 @@ namespace Emby.Server.Implementations.Data
         /// This holds all the types in the running assemblies
         /// so that we can de-serialize properly when we don't have strong types.
         /// </summary>
-        private readonly ConcurrentDictionary<string, Type> _typeMap = new ConcurrentDictionary<string, Type>();
+        private readonly ConcurrentDictionary<string, Type?> _typeMap = new ConcurrentDictionary<string, Type?>();
 
         /// <summary>
         /// Gets the type.
@@ -21,26 +21,16 @@ namespace Emby.Server.Implementations.Data
         /// <param name="typeName">Name of the type.</param>
         /// <returns>Type.</returns>
         /// <exception cref="ArgumentNullException"><c>typeName</c> is null.</exception>
-        public Type GetType(string typeName)
+        public Type? GetType(string typeName)
         {
             if (string.IsNullOrEmpty(typeName))
             {
                 throw new ArgumentNullException(nameof(typeName));
             }
 
-            return _typeMap.GetOrAdd(typeName, LookupType);
-        }
-
-        /// <summary>
-        /// Lookups the type.
-        /// </summary>
-        /// <param name="typeName">Name of the type.</param>
-        /// <returns>Type.</returns>
-        private Type LookupType(string typeName)
-        {
-            return AppDomain.CurrentDomain.GetAssemblies()
-                .Select(a => a.GetType(typeName))
-                .FirstOrDefault(t => t != null);
+            return _typeMap.GetOrAdd(typeName, k => AppDomain.CurrentDomain.GetAssemblies()
+                .Select(a => a.GetType(k))
+                .FirstOrDefault(t => t != null));
         }
     }
 }
diff --git a/Emby.Server.Implementations/Devices/DeviceId.cs b/Emby.Server.Implementations/Devices/DeviceId.cs
index fa6ac95fd..3d15b3e76 100644
--- a/Emby.Server.Implementations/Devices/DeviceId.cs
+++ b/Emby.Server.Implementations/Devices/DeviceId.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Dto/DtoService.cs b/Emby.Server.Implementations/Dto/DtoService.cs
index 4ae35039a..7411239a1 100644
--- a/Emby.Server.Implementations/Dto/DtoService.cs
+++ b/Emby.Server.Implementations/Dto/DtoService.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Emby.Server.Implementations.csproj b/Emby.Server.Implementations/Emby.Server.Implementations.csproj
index 14f6f565c..9c90de1ed 100644
--- a/Emby.Server.Implementations/Emby.Server.Implementations.csproj
+++ b/Emby.Server.Implementations/Emby.Server.Implementations.csproj
@@ -9,6 +9,7 @@
     <ProjectReference Include="..\Emby.Naming\Emby.Naming.csproj" />
     <ProjectReference Include="..\Emby.Notifications\Emby.Notifications.csproj" />
     <ProjectReference Include="..\Jellyfin.Api\Jellyfin.Api.csproj" />
+    <ProjectReference Include="..\Jellyfin.Server.Implementations\Jellyfin.Server.Implementations.csproj" />
     <ProjectReference Include="..\MediaBrowser.Model\MediaBrowser.Model.csproj" />
     <ProjectReference Include="..\MediaBrowser.Common\MediaBrowser.Common.csproj" />
     <ProjectReference Include="..\MediaBrowser.Controller\MediaBrowser.Controller.csproj" />
@@ -27,11 +28,11 @@
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="5.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="5.0.0" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="5.0.0" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="5.0.6" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="5.0.7" />
     <PackageReference Include="Mono.Nat" Version="3.0.1" />
     <PackageReference Include="prometheus-net.DotNetRuntime" Version="4.1.0" />
-    <PackageReference Include="sharpcompress" Version="0.28.2" />
-    <PackageReference Include="SQLitePCL.pretty.netstandard" Version="2.2.0" />
+    <PackageReference Include="sharpcompress" Version="0.28.3" />
+    <PackageReference Include="SQLitePCL.pretty.netstandard" Version="3.1.0" />
     <PackageReference Include="DotNet.Glob" Version="3.1.2" />
   </ItemGroup>
 
@@ -44,6 +45,7 @@
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <TreatWarningsAsErrors Condition=" '$(Configuration)' == 'Release'">true</TreatWarningsAsErrors>
+    <Nullable>enable</Nullable>
     <!-- https://github.com/microsoft/ApplicationInsights-dotnet/issues/2047 -->
     <NoWarn>AD0001</NoWarn>
     <AnalysisMode Condition=" '$(Configuration)' == 'Debug' ">AllEnabledByDefault</AnalysisMode>
diff --git a/Emby.Server.Implementations/EntryPoints/ExternalPortForwarding.cs b/Emby.Server.Implementations/EntryPoints/ExternalPortForwarding.cs
index 14201ead2..0a4efd73c 100644
--- a/Emby.Server.Implementations/EntryPoints/ExternalPortForwarding.cs
+++ b/Emby.Server.Implementations/EntryPoints/ExternalPortForwarding.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -106,8 +108,6 @@ namespace Emby.Server.Implementations.EntryPoints
             NatUtility.StartDiscovery();
 
             _timer = new Timer((_) => _createdRules.Clear(), null, TimeSpan.FromMinutes(10), TimeSpan.FromMinutes(10));
-
-            _deviceDiscovery.DeviceDiscovered += OnDeviceDiscoveryDeviceDiscovered;
         }
 
         private void Stop()
@@ -118,13 +118,6 @@ namespace Emby.Server.Implementations.EntryPoints
             NatUtility.DeviceFound -= OnNatUtilityDeviceFound;
 
             _timer?.Dispose();
-
-            _deviceDiscovery.DeviceDiscovered -= OnDeviceDiscoveryDeviceDiscovered;
-        }
-
-        private void OnDeviceDiscoveryDeviceDiscovered(object sender, GenericEventArgs<UpnpDeviceInfo> e)
-        {
-            NatUtility.Search(e.Argument.LocalIpAddress, NatProtocol.Upnp);
         }
 
         private async void OnNatUtilityDeviceFound(object sender, DeviceEventArgs e)
diff --git a/Emby.Server.Implementations/EntryPoints/LibraryChangedNotifier.cs b/Emby.Server.Implementations/EntryPoints/LibraryChangedNotifier.cs
index ae1b51b4c..5bb4100ba 100644
--- a/Emby.Server.Implementations/EntryPoints/LibraryChangedNotifier.cs
+++ b/Emby.Server.Implementations/EntryPoints/LibraryChangedNotifier.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/EntryPoints/RecordingNotifier.cs b/Emby.Server.Implementations/EntryPoints/RecordingNotifier.cs
index 824bb85f4..e0ca02d98 100644
--- a/Emby.Server.Implementations/EntryPoints/RecordingNotifier.cs
+++ b/Emby.Server.Implementations/EntryPoints/RecordingNotifier.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/EntryPoints/UdpServerEntryPoint.cs b/Emby.Server.Implementations/EntryPoints/UdpServerEntryPoint.cs
index 3624e079f..2e72b18f5 100644
--- a/Emby.Server.Implementations/EntryPoints/UdpServerEntryPoint.cs
+++ b/Emby.Server.Implementations/EntryPoints/UdpServerEntryPoint.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Net.Sockets;
 using System.Threading;
@@ -56,8 +54,8 @@ namespace Emby.Server.Implementations.EntryPoints
 
             try
             {
-                _udpServer = new UdpServer(_logger, _appHost, _config);
-                _udpServer.Start(PortNumber, _cancellationTokenSource.Token);
+                _udpServer = new UdpServer(_logger, _appHost, _config, PortNumber);
+                _udpServer.Start(_cancellationTokenSource.Token);
             }
             catch (SocketException ex)
             {
diff --git a/Emby.Server.Implementations/EntryPoints/UserDataChangeNotifier.cs b/Emby.Server.Implementations/EntryPoints/UserDataChangeNotifier.cs
index 1989e9ed2..d3bcd5e13 100644
--- a/Emby.Server.Implementations/EntryPoints/UserDataChangeNotifier.cs
+++ b/Emby.Server.Implementations/EntryPoints/UserDataChangeNotifier.cs
@@ -26,7 +26,7 @@ namespace Emby.Server.Implementations.EntryPoints
         private readonly Dictionary<Guid, List<BaseItem>> _changedItems = new Dictionary<Guid, List<BaseItem>>();
 
         private readonly object _syncLock = new object();
-        private Timer _updateTimer;
+        private Timer? _updateTimer;
 
         public UserDataChangeNotifier(IUserDataManager userDataManager, ISessionManager sessionManager, IUserManager userManager)
         {
@@ -42,7 +42,7 @@ namespace Emby.Server.Implementations.EntryPoints
             return Task.CompletedTask;
         }
 
-        void OnUserDataManagerUserDataSaved(object sender, UserDataSaveEventArgs e)
+        private void OnUserDataManagerUserDataSaved(object? sender, UserDataSaveEventArgs e)
         {
             if (e.SaveReason == UserDataSaveReason.PlaybackProgress)
             {
@@ -64,7 +64,7 @@ namespace Emby.Server.Implementations.EntryPoints
                     _updateTimer.Change(UpdateDuration, Timeout.Infinite);
                 }
 
-                if (!_changedItems.TryGetValue(e.UserId, out List<BaseItem> keys))
+                if (!_changedItems.TryGetValue(e.UserId, out List<BaseItem>? keys))
                 {
                     keys = new List<BaseItem>();
                     _changedItems[e.UserId] = keys;
@@ -87,7 +87,7 @@ namespace Emby.Server.Implementations.EntryPoints
             }
         }
 
-        private void UpdateTimerCallback(object state)
+        private void UpdateTimerCallback(object? state)
         {
             lock (_syncLock)
             {
diff --git a/Emby.Server.Implementations/HttpServer/Security/SessionContext.cs b/Emby.Server.Implementations/HttpServer/Security/SessionContext.cs
index cd1b9cba0..a7647caf9 100644
--- a/Emby.Server.Implementations/HttpServer/Security/SessionContext.cs
+++ b/Emby.Server.Implementations/HttpServer/Security/SessionContext.cs
@@ -43,14 +43,14 @@ namespace Emby.Server.Implementations.HttpServer.Security
             return GetSession((HttpContext)requestContext);
         }
 
-        public async Task<User> GetUser(HttpContext requestContext)
+        public async Task<User?> GetUser(HttpContext requestContext)
         {
             var session = await GetSession(requestContext).ConfigureAwait(false);
 
             return session == null || session.UserId.Equals(Guid.Empty) ? null : _userManager.GetUserById(session.UserId);
         }
 
-        public Task<User> GetUser(object requestContext)
+        public Task<User?> GetUser(object requestContext)
         {
             return GetUser(((HttpRequest)requestContext).HttpContext);
         }
diff --git a/Emby.Server.Implementations/HttpServer/WebSocketConnection.cs b/Emby.Server.Implementations/HttpServer/WebSocketConnection.cs
index 06acb5606..8f7d60669 100644
--- a/Emby.Server.Implementations/HttpServer/WebSocketConnection.cs
+++ b/Emby.Server.Implementations/HttpServer/WebSocketConnection.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Buffers;
 using System.IO.Pipelines;
diff --git a/Emby.Server.Implementations/HttpServer/WebSocketManager.cs b/Emby.Server.Implementations/HttpServer/WebSocketManager.cs
index b71ffdaee..f86bfd755 100644
--- a/Emby.Server.Implementations/HttpServer/WebSocketManager.cs
+++ b/Emby.Server.Implementations/HttpServer/WebSocketManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/IO/FileRefresher.cs b/Emby.Server.Implementations/IO/FileRefresher.cs
index 7435e9d0b..47a83d77c 100644
--- a/Emby.Server.Implementations/IO/FileRefresher.cs
+++ b/Emby.Server.Implementations/IO/FileRefresher.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/IO/LibraryMonitor.cs b/Emby.Server.Implementations/IO/LibraryMonitor.cs
index 3353fae9d..aa80bccd7 100644
--- a/Emby.Server.Implementations/IO/LibraryMonitor.cs
+++ b/Emby.Server.Implementations/IO/LibraryMonitor.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/IO/ManagedFileSystem.cs b/Emby.Server.Implementations/IO/ManagedFileSystem.cs
index 27096ed33..64d802457 100644
--- a/Emby.Server.Implementations/IO/ManagedFileSystem.cs
+++ b/Emby.Server.Implementations/IO/ManagedFileSystem.cs
@@ -7,6 +7,7 @@ using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
 using MediaBrowser.Common.Configuration;
+using MediaBrowser.Common.Extensions;
 using MediaBrowser.Model.IO;
 using MediaBrowser.Model.System;
 using Microsoft.Extensions.Logging;
@@ -61,7 +62,7 @@ namespace Emby.Server.Implementations.IO
         /// <param name="filename">The filename.</param>
         /// <returns>System.String.</returns>
         /// <exception cref="ArgumentNullException">filename</exception>
-        public virtual string ResolveShortcut(string filename)
+        public virtual string? ResolveShortcut(string filename)
         {
             if (string.IsNullOrEmpty(filename))
             {
@@ -243,8 +244,8 @@ namespace Emby.Server.Implementations.IO
                 {
                     result.Length = fileInfo.Length;
 
-                    // Issue #2354 get the size of files behind symbolic links
-                    if (fileInfo.Attributes.HasFlag(FileAttributes.ReparsePoint))
+                    // Issue #2354 get the size of files behind symbolic links. Also Enum.HasFlag is bad as it boxes!
+                    if ((fileInfo.Attributes & FileAttributes.ReparsePoint) == FileAttributes.ReparsePoint)
                     {
                         try
                         {
@@ -601,7 +602,7 @@ namespace Emby.Server.Implementations.IO
             return GetFiles(path, null, false, recursive);
         }
 
-        public virtual IEnumerable<FileSystemMetadata> GetFiles(string path, IReadOnlyList<string> extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
+        public virtual IEnumerable<FileSystemMetadata> GetFiles(string path, IReadOnlyList<string>? extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
         {
             var enumerationOptions = GetEnumerationOptions(recursive);
 
@@ -618,13 +619,13 @@ namespace Emby.Server.Implementations.IO
             {
                 files = files.Where(i =>
                 {
-                    var ext = i.Extension;
-                    if (ext == null)
+                    var ext = i.Extension.AsSpan();
+                    if (ext.IsEmpty)
                     {
                         return false;
                     }
 
-                    return extensions.Contains(ext, StringComparer.OrdinalIgnoreCase);
+                    return extensions.Contains(ext, StringComparison.OrdinalIgnoreCase);
                 });
             }
 
@@ -636,8 +637,7 @@ namespace Emby.Server.Implementations.IO
             var directoryInfo = new DirectoryInfo(path);
             var enumerationOptions = GetEnumerationOptions(recursive);
 
-            return ToMetadata(directoryInfo.EnumerateDirectories("*", enumerationOptions))
-                .Concat(ToMetadata(directoryInfo.EnumerateFiles("*", enumerationOptions)));
+            return ToMetadata(directoryInfo.EnumerateFileSystemInfos("*", enumerationOptions));
         }
 
         private IEnumerable<FileSystemMetadata> ToMetadata(IEnumerable<FileSystemInfo> infos)
@@ -655,7 +655,7 @@ namespace Emby.Server.Implementations.IO
             return GetFilePaths(path, null, false, recursive);
         }
 
-        public virtual IEnumerable<string> GetFilePaths(string path, string[] extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
+        public virtual IEnumerable<string> GetFilePaths(string path, string[]? extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
         {
             var enumerationOptions = GetEnumerationOptions(recursive);
 
@@ -672,13 +672,13 @@ namespace Emby.Server.Implementations.IO
             {
                 files = files.Where(i =>
                 {
-                    var ext = Path.GetExtension(i);
-                    if (ext == null)
+                    var ext = Path.GetExtension(i.AsSpan());
+                    if (ext.IsEmpty)
                     {
                         return false;
                     }
 
-                    return extensions.Contains(ext, StringComparer.OrdinalIgnoreCase);
+                    return extensions.Contains(ext, StringComparison.OrdinalIgnoreCase);
                 });
             }
 
diff --git a/Emby.Server.Implementations/IO/MbLinkShortcutHandler.cs b/Emby.Server.Implementations/IO/MbLinkShortcutHandler.cs
index e6696b8c4..76c58d5dc 100644
--- a/Emby.Server.Implementations/IO/MbLinkShortcutHandler.cs
+++ b/Emby.Server.Implementations/IO/MbLinkShortcutHandler.cs
@@ -17,7 +17,7 @@ namespace Emby.Server.Implementations.IO
 
         public string Extension => ".mblink";
 
-        public string Resolve(string shortcutPath)
+        public string? Resolve(string shortcutPath)
         {
             if (string.IsNullOrEmpty(shortcutPath))
             {
diff --git a/Emby.Server.Implementations/IO/StreamHelper.cs b/Emby.Server.Implementations/IO/StreamHelper.cs
index c16ebd61b..e4f5f4cf0 100644
--- a/Emby.Server.Implementations/IO/StreamHelper.cs
+++ b/Emby.Server.Implementations/IO/StreamHelper.cs
@@ -11,7 +11,7 @@ namespace Emby.Server.Implementations.IO
 {
     public class StreamHelper : IStreamHelper
     {
-        public async Task CopyToAsync(Stream source, Stream destination, int bufferSize, Action onStarted, CancellationToken cancellationToken)
+        public async Task CopyToAsync(Stream source, Stream destination, int bufferSize, Action? onStarted, CancellationToken cancellationToken)
         {
             byte[] buffer = ArrayPool<byte>.Shared.Rent(bufferSize);
             try
diff --git a/Emby.Server.Implementations/IStartupOptions.cs b/Emby.Server.Implementations/IStartupOptions.cs
index f719dc5f8..a430b9e72 100644
--- a/Emby.Server.Implementations/IStartupOptions.cs
+++ b/Emby.Server.Implementations/IStartupOptions.cs
@@ -1,5 +1,4 @@
 #pragma warning disable CS1591
-#nullable enable
 
 namespace Emby.Server.Implementations
 {
diff --git a/Emby.Server.Implementations/Images/BaseDynamicImageProvider.cs b/Emby.Server.Implementations/Images/BaseDynamicImageProvider.cs
index 6fa3c1c61..833fb0b7a 100644
--- a/Emby.Server.Implementations/Images/BaseDynamicImageProvider.cs
+++ b/Emby.Server.Implementations/Images/BaseDynamicImageProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Images/CollectionFolderImageProvider.cs b/Emby.Server.Implementations/Images/CollectionFolderImageProvider.cs
index 161b4c452..ff5f26ce0 100644
--- a/Emby.Server.Implementations/Images/CollectionFolderImageProvider.cs
+++ b/Emby.Server.Implementations/Images/CollectionFolderImageProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Images/DynamicImageProvider.cs b/Emby.Server.Implementations/Images/DynamicImageProvider.cs
index 50c531482..900b3fd9c 100644
--- a/Emby.Server.Implementations/Images/DynamicImageProvider.cs
+++ b/Emby.Server.Implementations/Images/DynamicImageProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Images/FolderImageProvider.cs b/Emby.Server.Implementations/Images/FolderImageProvider.cs
index 0224ab32a..859017f86 100644
--- a/Emby.Server.Implementations/Images/FolderImageProvider.cs
+++ b/Emby.Server.Implementations/Images/FolderImageProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Collections.Generic;
diff --git a/Emby.Server.Implementations/Images/GenreImageProvider.cs b/Emby.Server.Implementations/Images/GenreImageProvider.cs
index 381788231..6da431c68 100644
--- a/Emby.Server.Implementations/Images/GenreImageProvider.cs
+++ b/Emby.Server.Implementations/Images/GenreImageProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Collections.Generic;
diff --git a/Emby.Server.Implementations/Images/PlaylistImageProvider.cs b/Emby.Server.Implementations/Images/PlaylistImageProvider.cs
index a4c106e87..b8f0f0d65 100644
--- a/Emby.Server.Implementations/Images/PlaylistImageProvider.cs
+++ b/Emby.Server.Implementations/Images/PlaylistImageProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Collections.Generic;
diff --git a/Emby.Server.Implementations/Library/CoreResolutionIgnoreRule.cs b/Emby.Server.Implementations/Library/CoreResolutionIgnoreRule.cs
index 3380e29d4..c7d113963 100644
--- a/Emby.Server.Implementations/Library/CoreResolutionIgnoreRule.cs
+++ b/Emby.Server.Implementations/Library/CoreResolutionIgnoreRule.cs
@@ -77,7 +77,7 @@ namespace Emby.Server.Implementations.Library
                 if (parent != null)
                 {
                     // Don't resolve these into audio files
-                    if (string.Equals(Path.GetFileNameWithoutExtension(filename), BaseItem.ThemeSongFilename, StringComparison.Ordinal)
+                    if (Path.GetFileNameWithoutExtension(filename.AsSpan()).Equals(BaseItem.ThemeSongFilename, StringComparison.Ordinal)
                         && _libraryManager.IsAudioFile(filename))
                     {
                         return true;
diff --git a/Emby.Server.Implementations/Library/ExclusiveLiveStream.cs b/Emby.Server.Implementations/Library/ExclusiveLiveStream.cs
index 236453e80..6c65b5899 100644
--- a/Emby.Server.Implementations/Library/ExclusiveLiveStream.cs
+++ b/Emby.Server.Implementations/Library/ExclusiveLiveStream.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/IgnorePatterns.cs b/Emby.Server.Implementations/Library/IgnorePatterns.cs
index e30a67593..5384c04b3 100644
--- a/Emby.Server.Implementations/Library/IgnorePatterns.cs
+++ b/Emby.Server.Implementations/Library/IgnorePatterns.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Linq;
 using DotNet.Globbing;
diff --git a/Emby.Server.Implementations/Library/LibraryManager.cs b/Emby.Server.Implementations/Library/LibraryManager.cs
index 4d207471a..028673529 100644
--- a/Emby.Server.Implementations/Library/LibraryManager.cs
+++ b/Emby.Server.Implementations/Library/LibraryManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -694,25 +696,32 @@ namespace Emby.Server.Implementations.Library
         }
 
         private IEnumerable<BaseItem> ResolveFileList(
-            IEnumerable<FileSystemMetadata> fileList,
+            IReadOnlyList<FileSystemMetadata> fileList,
             IDirectoryService directoryService,
             Folder parent,
             string collectionType,
             IItemResolver[] resolvers,
             LibraryOptions libraryOptions)
         {
-            return fileList.Select(f =>
+            // Given that fileList is a list we can save enumerator allocations by indexing
+            for (var i = 0; i < fileList.Count; i++)
             {
+                var file = fileList[i];
+                BaseItem result = null;
                 try
                 {
-                    return ResolvePath(f, directoryService, resolvers, parent, collectionType, libraryOptions);
+                    result = ResolvePath(file, directoryService, resolvers, parent, collectionType, libraryOptions);
                 }
                 catch (Exception ex)
                 {
-                    _logger.LogError(ex, "Error resolving path {path}", f.FullName);
-                    return null;
+                    _logger.LogError(ex, "Error resolving path {Path}", file.FullName);
+                }
+
+                if (result != null)
+                {
+                    yield return result;
                 }
-            }).Where(i => i != null);
+            }
         }
 
         /// <summary>
@@ -1063,17 +1072,17 @@ namespace Emby.Server.Implementations.Library
             // Start by just validating the children of the root, but go no further
             await RootFolder.ValidateChildren(
                 new SimpleProgress<double>(),
-                cancellationToken,
                 new MetadataRefreshOptions(new DirectoryService(_fileSystem)),
-                recursive: false).ConfigureAwait(false);
+                recursive: false,
+                cancellationToken).ConfigureAwait(false);
 
             await GetUserRootFolder().RefreshMetadata(cancellationToken).ConfigureAwait(false);
 
             await GetUserRootFolder().ValidateChildren(
                 new SimpleProgress<double>(),
-                cancellationToken,
                 new MetadataRefreshOptions(new DirectoryService(_fileSystem)),
-                recursive: false).ConfigureAwait(false);
+                recursive: false,
+                cancellationToken).ConfigureAwait(false);
 
             // Quickly scan CollectionFolders for changes
             foreach (var folder in GetUserRootFolder().Children.OfType<Folder>())
@@ -1093,7 +1102,7 @@ namespace Emby.Server.Implementations.Library
             innerProgress.RegisterAction(pct => progress.Report(pct * 0.96));
 
             // Validate the entire media library
-            await RootFolder.ValidateChildren(innerProgress, cancellationToken, new MetadataRefreshOptions(new DirectoryService(_fileSystem)), recursive: true).ConfigureAwait(false);
+            await RootFolder.ValidateChildren(innerProgress, new MetadataRefreshOptions(new DirectoryService(_fileSystem)), recursive: true, cancellationToken).ConfigureAwait(false);
 
             progress.Report(96);
 
@@ -2074,7 +2083,7 @@ namespace Emby.Server.Implementations.Library
                 return new List<Folder>();
             }
 
-            return GetCollectionFoldersInternal(item, GetUserRootFolder().Children.OfType<Folder>().ToList());
+            return GetCollectionFoldersInternal(item, GetUserRootFolder().Children.OfType<Folder>());
         }
 
         public List<Folder> GetCollectionFolders(BaseItem item, List<Folder> allUserRootChildren)
@@ -2099,10 +2108,10 @@ namespace Emby.Server.Implementations.Library
             return GetCollectionFoldersInternal(item, allUserRootChildren);
         }
 
-        private static List<Folder> GetCollectionFoldersInternal(BaseItem item, List<Folder> allUserRootChildren)
+        private static List<Folder> GetCollectionFoldersInternal(BaseItem item, IEnumerable<Folder> allUserRootChildren)
         {
             return allUserRootChildren
-                .Where(i => string.Equals(i.Path, item.Path, StringComparison.OrdinalIgnoreCase) || i.PhysicalLocations.Contains(item.Path, StringComparer.OrdinalIgnoreCase))
+                .Where(i => string.Equals(i.Path, item.Path, StringComparison.OrdinalIgnoreCase) || i.PhysicalLocations.Contains(item.Path.AsSpan(), StringComparison.OrdinalIgnoreCase))
                 .ToList();
         }
 
@@ -2110,9 +2119,9 @@ namespace Emby.Server.Implementations.Library
         {
             if (!(item is CollectionFolder collectionFolder))
             {
+                // List.Find is more performant than FirstOrDefault due to enumerator allocation
                 collectionFolder = GetCollectionFolders(item)
-                   .OfType<CollectionFolder>()
-                   .FirstOrDefault();
+                    .Find(folder => folder is CollectionFolder) as CollectionFolder;
             }
 
             return collectionFolder == null ? new LibraryOptions() : collectionFolder.GetLibraryOptions();
@@ -2498,8 +2507,7 @@ namespace Emby.Server.Implementations.Library
         /// <inheritdoc />
         public bool IsVideoFile(string path)
         {
-            var resolver = new VideoResolver(GetNamingOptions());
-            return resolver.IsVideoFile(path);
+            return VideoResolver.IsVideoFile(path, GetNamingOptions());
         }
 
         /// <inheritdoc />
@@ -2677,6 +2685,7 @@ namespace Emby.Server.Implementations.Library
             return changed;
         }
 
+        /// <inheritdoc />
         public NamingOptions GetNamingOptions()
         {
             if (_namingOptions == null)
@@ -2690,13 +2699,12 @@ namespace Emby.Server.Implementations.Library
 
         public ItemLookupInfo ParseName(string name)
         {
-            var resolver = new VideoResolver(GetNamingOptions());
-
-            var result = resolver.CleanDateTime(name);
+            var namingOptions = GetNamingOptions();
+            var result = VideoResolver.CleanDateTime(name, namingOptions);
 
             return new ItemLookupInfo
             {
-                Name = resolver.TryCleanString(result.Name, out var newName) ? newName.ToString() : result.Name,
+                Name = VideoResolver.TryCleanString(result.Name, namingOptions, out var newName) ? newName.ToString() : result.Name,
                 Year = result.Year
             };
         }
@@ -2710,9 +2718,7 @@ namespace Emby.Server.Implementations.Library
                 .SelectMany(i => _fileSystem.GetFiles(i.FullName, _videoFileExtensions, false, false))
                 .ToList();
 
-            var videoListResolver = new VideoListResolver(namingOptions);
-
-            var videos = videoListResolver.Resolve(fileSystemChildren);
+            var videos = VideoListResolver.Resolve(fileSystemChildren, namingOptions);
 
             var currentVideo = videos.FirstOrDefault(i => string.Equals(owner.Path, i.Files[0].Path, StringComparison.OrdinalIgnoreCase));
 
@@ -2756,9 +2762,7 @@ namespace Emby.Server.Implementations.Library
                 .SelectMany(i => _fileSystem.GetFiles(i.FullName, _videoFileExtensions, false, false))
                 .ToList();
 
-            var videoListResolver = new VideoListResolver(namingOptions);
-
-            var videos = videoListResolver.Resolve(fileSystemChildren);
+            var videos = VideoListResolver.Resolve(fileSystemChildren, namingOptions);
 
             var currentVideo = videos.FirstOrDefault(i => string.Equals(owner.Path, i.Files[0].Path, StringComparison.OrdinalIgnoreCase));
 
diff --git a/Emby.Server.Implementations/Library/LiveStreamHelper.cs b/Emby.Server.Implementations/Library/LiveStreamHelper.cs
index c2951dd15..4ef7923db 100644
--- a/Emby.Server.Implementations/Library/LiveStreamHelper.cs
+++ b/Emby.Server.Implementations/Library/LiveStreamHelper.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/MediaSourceManager.cs b/Emby.Server.Implementations/Library/MediaSourceManager.cs
index 85d6d3043..b812b6b61 100644
--- a/Emby.Server.Implementations/Library/MediaSourceManager.cs
+++ b/Emby.Server.Implementations/Library/MediaSourceManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -350,7 +352,7 @@ namespace Emby.Server.Implementations.Library
 
         private string[] NormalizeLanguage(string language)
         {
-            if (language == null)
+            if (string.IsNullOrEmpty(language))
             {
                 return Array.Empty<string>();
             }
@@ -379,8 +381,7 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            var preferredSubs = string.IsNullOrEmpty(user.SubtitleLanguagePreference)
-                ? Array.Empty<string>() : NormalizeLanguage(user.SubtitleLanguagePreference);
+            var preferredSubs = NormalizeLanguage(user.SubtitleLanguagePreference);
 
             var defaultAudioIndex = source.DefaultAudioStreamIndex;
             var audioLangage = defaultAudioIndex == null
@@ -409,9 +410,7 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            var preferredAudio = string.IsNullOrEmpty(user.AudioLanguagePreference)
-                ? Array.Empty<string>()
-                : NormalizeLanguage(user.AudioLanguagePreference);
+            var preferredAudio = NormalizeLanguage(user.AudioLanguagePreference);
 
             source.DefaultAudioStreamIndex = MediaStreamSelector.GetDefaultAudioStreamIndex(source.MediaStreams, preferredAudio, user.PlayDefaultAudioTrack);
         }
diff --git a/Emby.Server.Implementations/Library/MediaStreamSelector.cs b/Emby.Server.Implementations/Library/MediaStreamSelector.cs
index 28fa06239..b833122ea 100644
--- a/Emby.Server.Implementations/Library/MediaStreamSelector.cs
+++ b/Emby.Server.Implementations/Library/MediaStreamSelector.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/MusicManager.cs b/Emby.Server.Implementations/Library/MusicManager.cs
index f8bae4fd1..06300adeb 100644
--- a/Emby.Server.Implementations/Library/MusicManager.cs
+++ b/Emby.Server.Implementations/Library/MusicManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/PathExtensions.cs b/Emby.Server.Implementations/Library/PathExtensions.cs
index 0de4edb7e..86b8039fa 100644
--- a/Emby.Server.Implementations/Library/PathExtensions.cs
+++ b/Emby.Server.Implementations/Library/PathExtensions.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Diagnostics.CodeAnalysis;
 using MediaBrowser.Common.Providers;
diff --git a/Emby.Server.Implementations/Library/ResolverHelper.cs b/Emby.Server.Implementations/Library/ResolverHelper.cs
index 1d9b44874..ac75e5d3a 100644
--- a/Emby.Server.Implementations/Library/ResolverHelper.cs
+++ b/Emby.Server.Implementations/Library/ResolverHelper.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.IO;
 using System.Linq;
diff --git a/Emby.Server.Implementations/Library/Resolvers/Audio/AudioResolver.cs b/Emby.Server.Implementations/Library/Resolvers/Audio/AudioResolver.cs
index 4ad84579d..e893d6335 100644
--- a/Emby.Server.Implementations/Library/Resolvers/Audio/AudioResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/Audio/AudioResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/Resolvers/Audio/MusicAlbumResolver.cs b/Emby.Server.Implementations/Library/Resolvers/Audio/MusicAlbumResolver.cs
index bf32381eb..8e1eccb10 100644
--- a/Emby.Server.Implementations/Library/Resolvers/Audio/MusicAlbumResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/Audio/MusicAlbumResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/Emby.Server.Implementations/Library/Resolvers/Audio/MusicArtistResolver.cs b/Emby.Server.Implementations/Library/Resolvers/Audio/MusicArtistResolver.cs
index 60f82806f..3d2ae95d2 100644
--- a/Emby.Server.Implementations/Library/Resolvers/Audio/MusicArtistResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/Audio/MusicArtistResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Linq;
 using System.Threading.Tasks;
diff --git a/Emby.Server.Implementations/Library/Resolvers/BaseVideoResolver.cs b/Emby.Server.Implementations/Library/Resolvers/BaseVideoResolver.cs
index 16050185f..cdb492022 100644
--- a/Emby.Server.Implementations/Library/Resolvers/BaseVideoResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/BaseVideoResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -45,11 +47,9 @@ namespace Emby.Server.Implementations.Library.Resolvers
         protected virtual TVideoType ResolveVideo<TVideoType>(ItemResolveArgs args, bool parseName)
               where TVideoType : Video, new()
         {
-            var namingOptions = ((LibraryManager)LibraryManager).GetNamingOptions();
+            var namingOptions = LibraryManager.GetNamingOptions();
 
             // If the path is a file check for a matching extensions
-            var parser = new VideoResolver(namingOptions);
-
             if (args.IsDirectory)
             {
                 TVideoType video = null;
@@ -64,7 +64,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
                     {
                         if (IsDvdDirectory(child.FullName, filename, args.DirectoryService))
                         {
-                            videoInfo = parser.ResolveDirectory(args.Path);
+                            videoInfo = VideoResolver.ResolveDirectory(args.Path, namingOptions);
 
                             if (videoInfo == null)
                             {
@@ -82,7 +82,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
 
                         if (IsBluRayDirectory(child.FullName, filename, args.DirectoryService))
                         {
-                            videoInfo = parser.ResolveDirectory(args.Path);
+                            videoInfo = VideoResolver.ResolveDirectory(args.Path, namingOptions);
 
                             if (videoInfo == null)
                             {
@@ -100,7 +100,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
                     }
                     else if (IsDvdFile(filename))
                     {
-                        videoInfo = parser.ResolveDirectory(args.Path);
+                        videoInfo = VideoResolver.ResolveDirectory(args.Path, namingOptions);
 
                         if (videoInfo == null)
                         {
@@ -130,7 +130,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
             }
             else
             {
-                var videoInfo = parser.Resolve(args.Path, false, false);
+                var videoInfo = VideoResolver.Resolve(args.Path, false, namingOptions, false);
 
                 if (videoInfo == null)
                 {
@@ -250,10 +250,7 @@ namespace Emby.Server.Implementations.Library.Resolvers
 
         protected void Set3DFormat(Video video)
         {
-            var namingOptions = ((LibraryManager)LibraryManager).GetNamingOptions();
-
-            var resolver = new Format3DParser(namingOptions);
-            var result = resolver.Parse(video.Path);
+            var result = Format3DParser.Parse(video.Path, LibraryManager.GetNamingOptions());
 
             Set3DFormat(video, result.Is3D, result.Format3D);
         }
diff --git a/Emby.Server.Implementations/Library/Resolvers/Books/BookResolver.cs b/Emby.Server.Implementations/Library/Resolvers/Books/BookResolver.cs
index 0525c7e30..68076730b 100644
--- a/Emby.Server.Implementations/Library/Resolvers/Books/BookResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/Books/BookResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/Resolvers/FolderResolver.cs b/Emby.Server.Implementations/Library/Resolvers/FolderResolver.cs
index 7dbce7a6e..7aaee017d 100644
--- a/Emby.Server.Implementations/Library/Resolvers/FolderResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/FolderResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Resolvers;
diff --git a/Emby.Server.Implementations/Library/Resolvers/ItemResolver.cs b/Emby.Server.Implementations/Library/Resolvers/ItemResolver.cs
index 92fb2a753..fa45ccf84 100644
--- a/Emby.Server.Implementations/Library/Resolvers/ItemResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/ItemResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Resolvers;
diff --git a/Emby.Server.Implementations/Library/Resolvers/Movies/BoxSetResolver.cs b/Emby.Server.Implementations/Library/Resolvers/Movies/BoxSetResolver.cs
index 295e9e120..69d71d0d9 100644
--- a/Emby.Server.Implementations/Library/Resolvers/Movies/BoxSetResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/Movies/BoxSetResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.IO;
 using MediaBrowser.Controller.Entities;
diff --git a/Emby.Server.Implementations/Library/Resolvers/Movies/MovieResolver.cs b/Emby.Server.Implementations/Library/Resolvers/Movies/MovieResolver.cs
index 16bf4dc4a..97f96f746 100644
--- a/Emby.Server.Implementations/Library/Resolvers/Movies/MovieResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/Movies/MovieResolver.cs
@@ -1,9 +1,12 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
 using Emby.Naming.Video;
+using MediaBrowser.Common.Extensions;
 using MediaBrowser.Controller.Drawing;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Entities.Movies;
@@ -255,10 +258,9 @@ namespace Emby.Server.Implementations.Library.Resolvers.Movies
                 }
             }
 
-            var namingOptions = ((LibraryManager)LibraryManager).GetNamingOptions();
+            var namingOptions = LibraryManager.GetNamingOptions();
 
-            var resolver = new VideoListResolver(namingOptions);
-            var resolverResult = resolver.Resolve(files, suppportMultiEditions).ToList();
+            var resolverResult = VideoListResolver.Resolve(files, namingOptions, suppportMultiEditions).ToList();
 
             var result = new MultiItemResolverResult
             {
@@ -535,7 +537,7 @@ namespace Emby.Server.Implementations.Library.Resolvers.Movies
             return returnVideo;
         }
 
-        private bool IsInvalid(Folder parent, string collectionType)
+        private bool IsInvalid(Folder parent, ReadOnlySpan<char> collectionType)
         {
             if (parent != null)
             {
@@ -545,12 +547,12 @@ namespace Emby.Server.Implementations.Library.Resolvers.Movies
                 }
             }
 
-            if (string.IsNullOrEmpty(collectionType))
+            if (collectionType.IsEmpty)
             {
                 return false;
             }
 
-            return !_validCollectionTypes.Contains(collectionType, StringComparer.OrdinalIgnoreCase);
+            return !_validCollectionTypes.Contains(collectionType, StringComparison.OrdinalIgnoreCase);
         }
     }
 }
diff --git a/Emby.Server.Implementations/Library/Resolvers/PhotoAlbumResolver.cs b/Emby.Server.Implementations/Library/Resolvers/PhotoAlbumResolver.cs
index 204c8a62e..534bc80dd 100644
--- a/Emby.Server.Implementations/Library/Resolvers/PhotoAlbumResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/PhotoAlbumResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using MediaBrowser.Controller.Drawing;
 using MediaBrowser.Controller.Entities;
diff --git a/Emby.Server.Implementations/Library/Resolvers/PhotoResolver.cs b/Emby.Server.Implementations/Library/Resolvers/PhotoResolver.cs
index 3cb6542cf..57bf40e9e 100644
--- a/Emby.Server.Implementations/Library/Resolvers/PhotoResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/PhotoResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/Resolvers/PlaylistResolver.cs b/Emby.Server.Implementations/Library/Resolvers/PlaylistResolver.cs
index 5f051321f..ecd44be47 100644
--- a/Emby.Server.Implementations/Library/Resolvers/PlaylistResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/PlaylistResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/Resolvers/SpecialFolderResolver.cs b/Emby.Server.Implementations/Library/Resolvers/SpecialFolderResolver.cs
index 99f304190..7b4e14334 100644
--- a/Emby.Server.Implementations/Library/Resolvers/SpecialFolderResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/SpecialFolderResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/Resolvers/TV/EpisodeResolver.cs b/Emby.Server.Implementations/Library/Resolvers/TV/EpisodeResolver.cs
index 6f29bc649..d6ae91056 100644
--- a/Emby.Server.Implementations/Library/Resolvers/TV/EpisodeResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/TV/EpisodeResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Linq;
 using MediaBrowser.Controller.Entities;
diff --git a/Emby.Server.Implementations/Library/Resolvers/TV/SeasonResolver.cs b/Emby.Server.Implementations/Library/Resolvers/TV/SeasonResolver.cs
index 768e2e4f5..7d707df18 100644
--- a/Emby.Server.Implementations/Library/Resolvers/TV/SeasonResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/TV/SeasonResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System.Globalization;
 using Emby.Naming.TV;
 using MediaBrowser.Controller.Entities.TV;
diff --git a/Emby.Server.Implementations/Library/Resolvers/TV/SeriesResolver.cs b/Emby.Server.Implementations/Library/Resolvers/TV/SeriesResolver.cs
index 8fc3e3e75..a1562abd3 100644
--- a/Emby.Server.Implementations/Library/Resolvers/TV/SeriesResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/TV/SeriesResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/Resolvers/VideoResolver.cs b/Emby.Server.Implementations/Library/Resolvers/VideoResolver.cs
index 62268fce9..9599faea4 100644
--- a/Emby.Server.Implementations/Library/Resolvers/VideoResolver.cs
+++ b/Emby.Server.Implementations/Library/Resolvers/VideoResolver.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using MediaBrowser.Controller.Entities;
diff --git a/Emby.Server.Implementations/Library/SearchEngine.cs b/Emby.Server.Implementations/Library/SearchEngine.cs
index bcdf854ca..26e615fa0 100644
--- a/Emby.Server.Implementations/Library/SearchEngine.cs
+++ b/Emby.Server.Implementations/Library/SearchEngine.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Library/UserDataManager.cs b/Emby.Server.Implementations/Library/UserDataManager.cs
index 827e3c64b..8aa605a90 100644
--- a/Emby.Server.Implementations/Library/UserDataManager.cs
+++ b/Emby.Server.Implementations/Library/UserDataManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -220,7 +222,7 @@ namespace Emby.Server.Implementations.Library
             var hasRuntime = runtimeTicks > 0;
 
             // If a position has been reported, and if we know the duration
-            if (positionTicks > 0 && hasRuntime && !(item is AudioBook))
+            if (positionTicks > 0 && hasRuntime && item is not AudioBook && item is not Book)
             {
                 var pctIn = decimal.Divide(positionTicks, runtimeTicks) * 100;
 
@@ -239,7 +241,7 @@ namespace Emby.Server.Implementations.Library
                 {
                     // Enforce MinResumeDuration
                     var durationSeconds = TimeSpan.FromTicks(runtimeTicks).TotalSeconds;
-                    if (durationSeconds < _config.Configuration.MinResumeDurationSeconds && !(item is Book))
+                    if (durationSeconds < _config.Configuration.MinResumeDurationSeconds)
                     {
                         positionTicks = 0;
                         data.Played = playedToCompletion = true;
diff --git a/Emby.Server.Implementations/Library/UserViewManager.cs b/Emby.Server.Implementations/Library/UserViewManager.cs
index ac041bcf6..e2da672a3 100644
--- a/Emby.Server.Implementations/Library/UserViewManager.cs
+++ b/Emby.Server.Implementations/Library/UserViewManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/EmbyTV/DirectRecorder.cs b/Emby.Server.Implementations/LiveTv/EmbyTV/DirectRecorder.cs
index 7a6b1d8b6..3fcadf5b1 100644
--- a/Emby.Server.Implementations/LiveTv/EmbyTV/DirectRecorder.cs
+++ b/Emby.Server.Implementations/LiveTv/EmbyTV/DirectRecorder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/EmbyTV/EmbyTV.cs b/Emby.Server.Implementations/LiveTv/EmbyTV/EmbyTV.cs
index 28a2095e1..797063120 100644
--- a/Emby.Server.Implementations/LiveTv/EmbyTV/EmbyTV.cs
+++ b/Emby.Server.Implementations/LiveTv/EmbyTV/EmbyTV.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs b/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs
index 9372b0f6c..26e4ef1ed 100644
--- a/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs
+++ b/Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/EmbyTV/EpgChannelData.cs b/Emby.Server.Implementations/LiveTv/EmbyTV/EpgChannelData.cs
index 8c27ca76e..0ec52a959 100644
--- a/Emby.Server.Implementations/LiveTv/EmbyTV/EpgChannelData.cs
+++ b/Emby.Server.Implementations/LiveTv/EmbyTV/EpgChannelData.cs
@@ -6,7 +6,6 @@ using MediaBrowser.Controller.LiveTv;
 
 namespace Emby.Server.Implementations.LiveTv.EmbyTV
 {
-
     internal class EpgChannelData
     {
 
@@ -39,13 +38,13 @@ namespace Emby.Server.Implementations.LiveTv.EmbyTV
             }
         }
 
-        public ChannelInfo GetChannelById(string id)
+        public ChannelInfo? GetChannelById(string id)
             => _channelsById.GetValueOrDefault(id);
 
-        public ChannelInfo GetChannelByNumber(string number)
+        public ChannelInfo? GetChannelByNumber(string number)
             => _channelsByNumber.GetValueOrDefault(number);
 
-        public ChannelInfo GetChannelByName(string name)
+        public ChannelInfo? GetChannelByName(string name)
             => _channelsByName.GetValueOrDefault(name);
 
         public static string NormalizeName(string value)
diff --git a/Emby.Server.Implementations/LiveTv/EmbyTV/ItemDataProvider.cs b/Emby.Server.Implementations/LiveTv/EmbyTV/ItemDataProvider.cs
index 1cac9cb96..bdab8c3e4 100644
--- a/Emby.Server.Implementations/LiveTv/EmbyTV/ItemDataProvider.cs
+++ b/Emby.Server.Implementations/LiveTv/EmbyTV/ItemDataProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/EmbyTV/TimerManager.cs b/Emby.Server.Implementations/LiveTv/EmbyTV/TimerManager.cs
index 1efa90e25..6c52a9a73 100644
--- a/Emby.Server.Implementations/LiveTv/EmbyTV/TimerManager.cs
+++ b/Emby.Server.Implementations/LiveTv/EmbyTV/TimerManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/Listings/SchedulesDirect.cs b/Emby.Server.Implementations/LiveTv/Listings/SchedulesDirect.cs
index 5b6f8cc49..cbdc7c707 100644
--- a/Emby.Server.Implementations/LiveTv/Listings/SchedulesDirect.cs
+++ b/Emby.Server.Implementations/LiveTv/Listings/SchedulesDirect.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/Listings/XmlTvListingsProvider.cs b/Emby.Server.Implementations/LiveTv/Listings/XmlTvListingsProvider.cs
index 6824aa442..ebad4eddf 100644
--- a/Emby.Server.Implementations/LiveTv/Listings/XmlTvListingsProvider.cs
+++ b/Emby.Server.Implementations/LiveTv/Listings/XmlTvListingsProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/LiveTvConfigurationFactory.cs b/Emby.Server.Implementations/LiveTv/LiveTvConfigurationFactory.cs
index ba916af38..098f193fb 100644
--- a/Emby.Server.Implementations/LiveTv/LiveTvConfigurationFactory.cs
+++ b/Emby.Server.Implementations/LiveTv/LiveTvConfigurationFactory.cs
@@ -1,21 +1,23 @@
-#pragma warning disable CS1591
-
 using System.Collections.Generic;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Model.LiveTv;
 
 namespace Emby.Server.Implementations.LiveTv
 {
+    /// <summary>
+    /// <see cref="IConfigurationFactory" /> implementation for <see cref="LiveTvOptions" />.
+    /// </summary>
     public class LiveTvConfigurationFactory : IConfigurationFactory
     {
+        /// <inheritdoc />
         public IEnumerable<ConfigurationStore> GetConfigurations()
         {
             return new ConfigurationStore[]
             {
                 new ConfigurationStore
                 {
-                     ConfigurationType = typeof(LiveTvOptions),
-                     Key = "livetv"
+                    ConfigurationType = typeof(LiveTvOptions),
+                    Key = "livetv"
                 }
             };
         }
diff --git a/Emby.Server.Implementations/LiveTv/LiveTvDtoService.cs b/Emby.Server.Implementations/LiveTv/LiveTvDtoService.cs
index 6af49dd45..21e1409ac 100644
--- a/Emby.Server.Implementations/LiveTv/LiveTvDtoService.cs
+++ b/Emby.Server.Implementations/LiveTv/LiveTvDtoService.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/LiveTvManager.cs b/Emby.Server.Implementations/LiveTv/LiveTvManager.cs
index 1145d8aa1..d964769b5 100644
--- a/Emby.Server.Implementations/LiveTv/LiveTvManager.cs
+++ b/Emby.Server.Implementations/LiveTv/LiveTvManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -2264,7 +2266,7 @@ namespace Emby.Server.Implementations.LiveTv
 
             if (dataSourceChanged)
             {
-                _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+                _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
             }
 
             return info;
@@ -2307,7 +2309,7 @@ namespace Emby.Server.Implementations.LiveTv
 
             _config.SaveConfiguration("livetv", config);
 
-            _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+            _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
 
             return info;
         }
@@ -2319,7 +2321,7 @@ namespace Emby.Server.Implementations.LiveTv
             config.ListingProviders = config.ListingProviders.Where(i => !string.Equals(id, i.Id, StringComparison.OrdinalIgnoreCase)).ToArray();
 
             _config.SaveConfiguration("livetv", config);
-            _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+            _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
         }
 
         public async Task<TunerChannelMapping> SetChannelMapping(string providerId, string tunerChannelId, string providerChannelId)
@@ -2353,7 +2355,7 @@ namespace Emby.Server.Implementations.LiveTv
             var tunerChannelMappings =
                 tunerChannels.Select(i => GetTunerChannelMapping(i, mappings, providerChannels)).ToList();
 
-            _taskManager.CancelIfRunningAndQueue<RefreshChannelsScheduledTask>();
+            _taskManager.CancelIfRunningAndQueue<RefreshGuideScheduledTask>();
 
             return tunerChannelMappings.First(i => string.Equals(i.Id, tunerChannelId, StringComparison.OrdinalIgnoreCase));
         }
diff --git a/Emby.Server.Implementations/LiveTv/LiveTvMediaSourceProvider.cs b/Emby.Server.Implementations/LiveTv/LiveTvMediaSourceProvider.cs
index 3a738fd5d..ecd28097d 100644
--- a/Emby.Server.Implementations/LiveTv/LiveTvMediaSourceProvider.cs
+++ b/Emby.Server.Implementations/LiveTv/LiveTvMediaSourceProvider.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/RefreshChannelsScheduledTask.cs b/Emby.Server.Implementations/LiveTv/RefreshGuideScheduledTask.cs
index 582b64923..15df0dcf1 100644
--- a/Emby.Server.Implementations/LiveTv/RefreshChannelsScheduledTask.cs
+++ b/Emby.Server.Implementations/LiveTv/RefreshGuideScheduledTask.cs
@@ -1,7 +1,6 @@
-#pragma warning disable CS1591
-
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Controller.LiveTv;
@@ -10,34 +9,55 @@ using MediaBrowser.Model.Tasks;
 
 namespace Emby.Server.Implementations.LiveTv
 {
-    public class RefreshChannelsScheduledTask : IScheduledTask, IConfigurableScheduledTask
+    /// <summary>
+    /// The "Refresh Guide" scheduled task.
+    /// </summary>
+    public class RefreshGuideScheduledTask : IScheduledTask, IConfigurableScheduledTask
     {
         private readonly ILiveTvManager _liveTvManager;
         private readonly IConfigurationManager _config;
 
-        public RefreshChannelsScheduledTask(ILiveTvManager liveTvManager, IConfigurationManager config)
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RefreshGuideScheduledTask"/> class.
+        /// </summary>
+        /// <param name="liveTvManager">The live tv manager.</param>
+        /// <param name="config">The configuration manager.</param>
+        public RefreshGuideScheduledTask(ILiveTvManager liveTvManager, IConfigurationManager config)
         {
             _liveTvManager = liveTvManager;
             _config = config;
         }
 
+        /// <inheritdoc />
         public string Name => "Refresh Guide";
 
+        /// <inheritdoc />
         public string Description => "Downloads channel information from live tv services.";
 
+        /// <inheritdoc />
         public string Category => "Live TV";
 
-        public Task Execute(System.Threading.CancellationToken cancellationToken, IProgress<double> progress)
+        /// <inheritdoc />
+        public bool IsHidden => _liveTvManager.Services.Count == 1 && GetConfiguration().TunerHosts.Length == 0;
+
+        /// <inheritdoc />
+        public bool IsEnabled => true;
+
+        /// <inheritdoc />
+        public bool IsLogged => true;
+
+        /// <inheritdoc />
+        public string Key => "RefreshGuide";
+
+        /// <inheritdoc />
+        public Task Execute(CancellationToken cancellationToken, IProgress<double> progress)
         {
             var manager = (LiveTvManager)_liveTvManager;
 
             return manager.RefreshChannels(progress, cancellationToken);
         }
 
-        /// <summary>
-        /// Creates the triggers that define when the task will run.
-        /// </summary>
-        /// <returns>IEnumerable{BaseTaskTrigger}.</returns>
+        /// <inheritdoc />
         public IEnumerable<TaskTriggerInfo> GetDefaultTriggers()
         {
             return new[]
@@ -51,13 +71,5 @@ namespace Emby.Server.Implementations.LiveTv
         {
             return _config.GetConfiguration<LiveTvOptions>("livetv");
         }
-
-        public bool IsHidden => _liveTvManager.Services.Count == 1 && GetConfiguration().TunerHosts.Length == 0;
-
-        public bool IsEnabled => true;
-
-        public bool IsLogged => true;
-
-        public string Key => "RefreshGuide";
     }
 }
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/BaseTunerHost.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/BaseTunerHost.cs
index fbcd4ef37..5941613cf 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/BaseTunerHost.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/BaseTunerHost.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -38,6 +40,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
         public virtual bool IsSupported => true;
 
         protected abstract Task<List<ChannelInfo>> GetChannelsInternal(TunerHostInfo tuner, CancellationToken cancellationToken);
+
         public abstract string Type { get; }
 
         public async Task<List<ChannelInfo>> GetChannels(TunerHostInfo tuner, bool enableCache, CancellationToken cancellationToken)
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/Channels.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/Channels.cs
index 740cbb66e..0f0453189 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/Channels.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/Channels.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
 {
     internal class Channels
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/DiscoverResponse.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/DiscoverResponse.cs
index 09d77f838..42068cd34 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/DiscoverResponse.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/DiscoverResponse.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 
 namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunHost.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunHost.cs
index bbac6e055..54de841fe 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunHost.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunHost.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -581,7 +583,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
                     Logger,
                     Config,
                     _appHost,
-                    _networkManager,
                     _streamHelper);
             }
 
@@ -622,7 +623,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
                 Logger,
                 Config,
                 _appHost,
-                _networkManager,
                 _streamHelper);
         }
 
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs
index a7fda1d72..3016eeda2 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunUdpStream.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunUdpStream.cs
index b16ccc561..58e0c7448 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunUdpStream.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/HdHomerun/HdHomerunUdpStream.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -10,7 +12,6 @@ using System.Net.Sockets;
 using System.Threading;
 using System.Threading.Tasks;
 using MediaBrowser.Common.Configuration;
-using MediaBrowser.Common.Net;
 using MediaBrowser.Controller;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Model.Dto;
@@ -28,7 +29,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
         private readonly IServerApplicationHost _appHost;
         private readonly IHdHomerunChannelCommands _channelCommands;
         private readonly int _numTuners;
-        private readonly INetworkManager _networkManager;
 
         public HdHomerunUdpStream(
             MediaSourceInfo mediaSource,
@@ -40,12 +40,10 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
             ILogger logger,
             IConfigurationManager configurationManager,
             IServerApplicationHost appHost,
-            INetworkManager networkManager,
             IStreamHelper streamHelper)
             : base(mediaSource, tunerHostInfo, fileSystem, logger, configurationManager, streamHelper)
         {
             _appHost = appHost;
-            _networkManager = networkManager;
             OriginalStreamId = originalStreamId;
             _channelCommands = channelCommands;
             _numTuners = numTuners;
@@ -126,7 +124,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts.HdHomerun
                 using (udpClient)
                 using (hdHomerunManager)
                 {
-                    if (!(ex is OperationCanceledException))
+                    if (ex is not OperationCanceledException)
                     {
                         Logger.LogError(ex, "Error opening live stream:");
                     }
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/LiveStream.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/LiveStream.cs
index f8baf55da..96a678c1d 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/LiveStream.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/LiveStream.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/M3UTunerHost.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/M3UTunerHost.cs
index 4b170b2e4..8fa6f5ad6 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/M3UTunerHost.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/M3UTunerHost.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -27,6 +29,14 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 {
     public class M3UTunerHost : BaseTunerHost, ITunerHost, IConfigurableTunerHost
     {
+        private static readonly string[] _disallowedSharedStreamExtensions =
+        {
+            ".mkv",
+            ".mp4",
+            ".m3u8",
+            ".mpd"
+        };
+
         private readonly IHttpClientFactory _httpClientFactory;
         private readonly IServerApplicationHost _appHost;
         private readonly INetworkManager _networkManager;
@@ -65,7 +75,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
         {
             var channelIdPrefix = GetFullChannelIdPrefix(info);
 
-            return await new M3uParser(Logger, _httpClientFactory, _appHost)
+            return await new M3uParser(Logger, _httpClientFactory)
                 .Parse(info, channelIdPrefix, cancellationToken)
                 .ConfigureAwait(false);
         }
@@ -86,14 +96,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
             return Task.FromResult(list);
         }
 
-        private static readonly string[] _disallowedSharedStreamExtensions =
-        {
-            ".mkv",
-            ".mp4",
-            ".m3u8",
-            ".mpd"
-        };
-
         protected override async Task<ILiveStream> GetChannelStream(TunerHostInfo info, ChannelInfo channelInfo, string streamId, List<ILiveStream> currentLiveStreams, CancellationToken cancellationToken)
         {
             var tunerCount = info.TunerCount;
@@ -128,7 +130,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 
         public async Task Validate(TunerHostInfo info)
         {
-            using (var stream = await new M3uParser(Logger, _httpClientFactory, _appHost).GetListingsStream(info, CancellationToken.None).ConfigureAwait(false))
+            using (var stream = await new M3uParser(Logger, _httpClientFactory).GetListingsStream(info, CancellationToken.None).ConfigureAwait(false))
             {
             }
         }
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs
index 84d416149..40a162890 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/M3uParser.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -19,15 +21,15 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 {
     public class M3uParser
     {
+        private const string ExtInfPrefix = "#EXTINF:";
+
         private readonly ILogger _logger;
         private readonly IHttpClientFactory _httpClientFactory;
-        private readonly IServerApplicationHost _appHost;
 
-        public M3uParser(ILogger logger, IHttpClientFactory httpClientFactory, IServerApplicationHost appHost)
+        public M3uParser(ILogger logger, IHttpClientFactory httpClientFactory)
         {
             _logger = logger;
             _httpClientFactory = httpClientFactory;
-            _appHost = appHost;
         }
 
         public async Task<List<ChannelInfo>> Parse(TunerHostInfo info, string channelIdPrefix, CancellationToken cancellationToken)
@@ -59,8 +61,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
             return File.OpenRead(info.Url);
         }
 
-        private const string ExtInfPrefix = "#EXTINF:";
-
         private async Task<List<ChannelInfo>> GetChannelsAsync(TextReader reader, string channelIdPrefix, string tunerHostId)
         {
             var channels = new List<ChannelInfo>();
diff --git a/Emby.Server.Implementations/LiveTv/TunerHosts/SharedHttpStream.cs b/Emby.Server.Implementations/LiveTv/TunerHosts/SharedHttpStream.cs
index eeb2426f4..f572151b8 100644
--- a/Emby.Server.Implementations/LiveTv/TunerHosts/SharedHttpStream.cs
+++ b/Emby.Server.Implementations/LiveTv/TunerHosts/SharedHttpStream.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -89,8 +91,6 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
 
             var taskCompletionSource = new TaskCompletionSource<bool>();
 
-            var now = DateTime.UtcNow;
-
             _ = StartStreaming(response, taskCompletionSource, LiveStreamCancellationTokenSource.Token);
 
             // OpenedMediaSource.Protocol = MediaProtocol.File;
@@ -118,7 +118,7 @@ namespace Emby.Server.Implementations.LiveTv.TunerHosts
             if (!taskCompletionSource.Task.Result)
             {
                 Logger.LogWarning("Zero bytes copied from stream {0} to {1} but no exception raised", GetType().Name, TempFilePath);
-                throw new EndOfStreamException(String.Format(CultureInfo.InvariantCulture, "Zero bytes copied from stream {0}", GetType().Name));
+                throw new EndOfStreamException(string.Format(CultureInfo.InvariantCulture, "Zero bytes copied from stream {0}", GetType().Name));
             }
         }
 
diff --git a/Emby.Server.Implementations/Localization/Core/ar.json b/Emby.Server.Implementations/Localization/Core/ar.json
index 9f84d3a3c..3d6e159b1 100644
--- a/Emby.Server.Implementations/Localization/Core/ar.json
+++ b/Emby.Server.Implementations/Localization/Core/ar.json
@@ -116,5 +116,7 @@
     "TaskCleanLogs": "حذف دليل السجل",
     "TaskCleanActivityLogDescription": "يحذف سجل الأنشطة الأقدم من الوقت الموضوع.",
     "TaskCleanActivityLog": "حذف سجل الأنشطة",
-    "Default": "الإعدادات الافتراضية"
+    "Default": "الإعدادات الافتراضية",
+    "Undefined": "غير معرف",
+    "Forced": "ملحقة"
 }
diff --git a/Emby.Server.Implementations/Localization/Core/en-US.json b/Emby.Server.Implementations/Localization/Core/en-US.json
index f8f595faa..65964f6d9 100644
--- a/Emby.Server.Implementations/Localization/Core/en-US.json
+++ b/Emby.Server.Implementations/Localization/Core/en-US.json
@@ -117,5 +117,7 @@
     "TaskRefreshChannels": "Refresh Channels",
     "TaskRefreshChannelsDescription": "Refreshes internet channel information.",
     "TaskDownloadMissingSubtitles": "Download missing subtitles",
-    "TaskDownloadMissingSubtitlesDescription": "Searches the internet for missing subtitles based on metadata configuration."
+    "TaskDownloadMissingSubtitlesDescription": "Searches the internet for missing subtitles based on metadata configuration.",
+    "TaskOptimizeDatabase": "Optimize database",
+    "TaskOptimizeDatabaseDescription": "Compacts database and truncates free space. Running this task after scanning the library or doing other changes that imply database modifications might improve performance."
 }
diff --git a/Emby.Server.Implementations/Localization/Core/es.json b/Emby.Server.Implementations/Localization/Core/es.json
index 16fde325f..91939843f 100644
--- a/Emby.Server.Implementations/Localization/Core/es.json
+++ b/Emby.Server.Implementations/Localization/Core/es.json
@@ -118,5 +118,7 @@
     "TaskCleanActivityLog": "Limpiar registro de actividad",
     "Undefined": "Indefinido",
     "Forced": "Forzado",
-    "Default": "Predeterminado"
+    "Default": "Predeterminado",
+    "TaskOptimizeDatabase": "Optimizar la base de datos",
+    "TaskOptimizeDatabaseDescription": "Compacta y libera el espacio libre en la base de datos. Ejecutar esta tarea tras escanear la biblioteca o hacer cambios que impliquen modificaciones en la base de datos puede mejorar el rendimiento."
 }
diff --git a/Emby.Server.Implementations/Localization/Core/nn.json b/Emby.Server.Implementations/Localization/Core/nn.json
index f5683f35b..32d4f3a8b 100644
--- a/Emby.Server.Implementations/Localization/Core/nn.json
+++ b/Emby.Server.Implementations/Localization/Core/nn.json
@@ -29,9 +29,9 @@
     "Collections": "Samlingar",
     "ChapterNameValue": "Kapittel {0}",
     "Channels": "Kanalar",
-    "CameraImageUploadedFrom": "Eit nytt kamera bilete har blitt lasta opp frå {0}",
+    "CameraImageUploadedFrom": "Eit nytt kamerabilete har blitt lasta opp frå {0}",
     "Books": "Bøker",
-    "AuthenticationSucceededWithUserName": "{0} Har logga inn",
+    "AuthenticationSucceededWithUserName": "{0} har logga inn",
     "Artists": "Artistar",
     "Application": "Program",
     "AppDeviceValues": "App: {0}, Eining: {1}",
diff --git a/Emby.Server.Implementations/Localization/LocalizationManager.cs b/Emby.Server.Implementations/Localization/LocalizationManager.cs
index 220e423bf..b1ff28c2c 100644
--- a/Emby.Server.Implementations/Localization/LocalizationManager.cs
+++ b/Emby.Server.Implementations/Localization/LocalizationManager.cs
@@ -1,9 +1,10 @@
+#nullable disable
+
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
-using System.Linq;
 using System.Reflection;
 using System.Text.Json;
 using System.Threading.Tasks;
@@ -167,12 +168,22 @@ namespace Emby.Server.Implementations.Localization
 
         /// <inheritdoc />
         public CultureDto FindLanguageInfo(string language)
-            => GetCultures()
-                .FirstOrDefault(i =>
-                    string.Equals(i.DisplayName, language, StringComparison.OrdinalIgnoreCase)
-                    || string.Equals(i.Name, language, StringComparison.OrdinalIgnoreCase)
-                    || i.ThreeLetterISOLanguageNames.Contains(language, StringComparer.OrdinalIgnoreCase)
-                    || string.Equals(i.TwoLetterISOLanguageName, language, StringComparison.OrdinalIgnoreCase));
+        {
+            // TODO language should ideally be a ReadOnlySpan but moq cannot mock ref structs
+            for (var i = 0; i < _cultures.Count; i++)
+            {
+                var culture = _cultures[i];
+                if (language.Equals(culture.DisplayName, StringComparison.OrdinalIgnoreCase)
+                    || language.Equals(culture.Name, StringComparison.OrdinalIgnoreCase)
+                    || culture.ThreeLetterISOLanguageNames.Contains(language, StringComparison.OrdinalIgnoreCase)
+                    || language.Equals(culture.TwoLetterISOLanguageName, StringComparison.OrdinalIgnoreCase))
+                {
+                    return culture;
+                }
+            }
+
+            return default;
+        }
 
         /// <inheritdoc />
         public IEnumerable<CountryInfo> GetCountries()
@@ -222,7 +233,7 @@ namespace Emby.Server.Implementations.Localization
                 throw new ArgumentNullException(nameof(rating));
             }
 
-            if (_unratedValues.Contains(rating, StringComparer.OrdinalIgnoreCase))
+            if (_unratedValues.Contains(rating.AsSpan(), StringComparison.OrdinalIgnoreCase))
             {
                 return null;
             }
@@ -250,11 +261,11 @@ namespace Emby.Server.Implementations.Localization
             var index = rating.IndexOf(':', StringComparison.Ordinal);
             if (index != -1)
             {
-                rating = rating.Substring(index).TrimStart(':').Trim();
+                var trimmedRating = rating.AsSpan(index).TrimStart(':').Trim();
 
-                if (!string.IsNullOrWhiteSpace(rating))
+                if (!trimmedRating.IsEmpty)
                 {
-                    return GetRatingLevel(rating);
+                    return GetRatingLevel(trimmedRating.ToString());
                 }
             }
 
@@ -316,7 +327,8 @@ namespace Emby.Server.Implementations.Localization
 
             return _dictionaries.GetOrAdd(
                 culture,
-                f => GetDictionary(Prefix, culture, DefaultCulture + ".json").GetAwaiter().GetResult());
+                (key, localizationManager) => localizationManager.GetDictionary(Prefix, key, DefaultCulture + ".json").GetAwaiter().GetResult(),
+                this);
         }
 
         private async Task<Dictionary<string, string>> GetDictionary(string prefix, string culture, string baseFilename)
diff --git a/Emby.Server.Implementations/MediaEncoder/EncodingManager.cs b/Emby.Server.Implementations/MediaEncoder/EncodingManager.cs
index 031b5d2e7..8aaa1f7bb 100644
--- a/Emby.Server.Implementations/MediaEncoder/EncodingManager.cs
+++ b/Emby.Server.Implementations/MediaEncoder/EncodingManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Net/SocketFactory.cs b/Emby.Server.Implementations/Net/SocketFactory.cs
index 0781a0e33..137728616 100644
--- a/Emby.Server.Implementations/Net/SocketFactory.cs
+++ b/Emby.Server.Implementations/Net/SocketFactory.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Net/UdpSocket.cs b/Emby.Server.Implementations/Net/UdpSocket.cs
index 4e25768cf..a8b18d292 100644
--- a/Emby.Server.Implementations/Net/UdpSocket.cs
+++ b/Emby.Server.Implementations/Net/UdpSocket.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Playlists/PlaylistManager.cs b/Emby.Server.Implementations/Playlists/PlaylistManager.cs
index 2d1a559f1..9a1ca9946 100644
--- a/Emby.Server.Implementations/Playlists/PlaylistManager.cs
+++ b/Emby.Server.Implementations/Playlists/PlaylistManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Plugins/PluginManager.cs b/Emby.Server.Implementations/Plugins/PluginManager.cs
index 14df20936..8fd61f2bc 100644
--- a/Emby.Server.Implementations/Plugins/PluginManager.cs
+++ b/Emby.Server.Implementations/Plugins/PluginManager.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Collections.Generic;
 using System.Globalization;
@@ -396,7 +394,7 @@ namespace Emby.Server.Implementations.Plugins
                 Category = packageInfo.Category,
                 Changelog = versionInfo.Changelog ?? string.Empty,
                 Description = packageInfo.Description,
-                Id = new Guid(packageInfo.Id),
+                Id = packageInfo.Id,
                 Name = packageInfo.Name,
                 Overview = packageInfo.Overview,
                 Owner = packageInfo.Owner,
@@ -457,7 +455,8 @@ namespace Emby.Server.Implementations.Plugins
             try
             {
                 _logger.LogDebug("Creating instance of {Type}", type);
-                var instance = (IPlugin)ActivatorUtilities.CreateInstance(_appHost.ServiceProvider, type);
+                // _appHost.ServiceProvider is already assigned when we create the plugins
+                var instance = (IPlugin)ActivatorUtilities.CreateInstance(_appHost.ServiceProvider!, type);
                 if (plugin == null)
                 {
                     // Create a dummy record for the providers.
diff --git a/Emby.Server.Implementations/QuickConnect/QuickConnectManager.cs b/Emby.Server.Implementations/QuickConnect/QuickConnectManager.cs
index c627bc3fc..b32c70eb9 100644
--- a/Emby.Server.Implementations/QuickConnect/QuickConnectManager.cs
+++ b/Emby.Server.Implementations/QuickConnect/QuickConnectManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -127,6 +129,7 @@ namespace Emby.Server.Implementations.QuickConnect
             return result;
         }
 
+        /// <inheritdoc/>
         public void AuthenticateRequest(AuthenticationRequest request, string token)
         {
             if (!_quickConnectTokens.TryGetValue(token, out var entry))
diff --git a/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs b/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs
index 101d9b537..d7e320754 100644
--- a/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -709,11 +711,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
                     throw new ArgumentException("Info did not contain a TimeOfDayTicks.", nameof(info));
                 }
 
-                return new DailyTrigger
-                {
-                    TimeOfDay = TimeSpan.FromTicks(info.TimeOfDayTicks.Value),
-                    TaskOptions = options
-                };
+                return new DailyTrigger(TimeSpan.FromTicks(info.TimeOfDayTicks.Value), options);
             }
 
             if (info.Type.Equals(nameof(WeeklyTrigger), StringComparison.OrdinalIgnoreCase))
@@ -728,12 +726,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
                     throw new ArgumentException("Info did not contain a DayOfWeek.", nameof(info));
                 }
 
-                return new WeeklyTrigger
-                {
-                    TimeOfDay = TimeSpan.FromTicks(info.TimeOfDayTicks.Value),
-                    DayOfWeek = info.DayOfWeek.Value,
-                    TaskOptions = options
-                };
+                return new WeeklyTrigger(TimeSpan.FromTicks(info.TimeOfDayTicks.Value), info.DayOfWeek.Value, options);
             }
 
             if (info.Type.Equals(nameof(IntervalTrigger), StringComparison.OrdinalIgnoreCase))
@@ -743,16 +736,12 @@ namespace Emby.Server.Implementations.ScheduledTasks
                     throw new ArgumentException("Info did not contain a IntervalTicks.", nameof(info));
                 }
 
-                return new IntervalTrigger
-                {
-                    Interval = TimeSpan.FromTicks(info.IntervalTicks.Value),
-                    TaskOptions = options
-                };
+                return new IntervalTrigger(TimeSpan.FromTicks(info.IntervalTicks.Value), options);
             }
 
             if (info.Type.Equals(nameof(StartupTrigger), StringComparison.OrdinalIgnoreCase))
             {
-                return new StartupTrigger();
+                return new StartupTrigger(options);
             }
 
             throw new ArgumentException("Unrecognized trigger type: " + info.Type);
diff --git a/Emby.Server.Implementations/ScheduledTasks/TaskManager.cs b/Emby.Server.Implementations/ScheduledTasks/TaskManager.cs
index af316e108..4f0df75bf 100644
--- a/Emby.Server.Implementations/ScheduledTasks/TaskManager.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/TaskManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/ScheduledTasks/Tasks/ChapterImagesTask.cs b/Emby.Server.Implementations/ScheduledTasks/Tasks/ChapterImagesTask.cs
index 2312c85d9..baeb86a22 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Tasks/ChapterImagesTask.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Tasks/ChapterImagesTask.cs
@@ -140,8 +140,10 @@ namespace Emby.Server.Implementations.ScheduledTasks
                         previouslyFailedImages.Add(key);
 
                         var parentPath = Path.GetDirectoryName(failHistoryPath);
-
-                        Directory.CreateDirectory(parentPath);
+                        if (parentPath != null)
+                        {
+                            Directory.CreateDirectory(parentPath);
+                        }
 
                         string text = string.Join('|', previouslyFailedImages);
                         File.WriteAllText(failHistoryPath, text);
diff --git a/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanActivityLogTask.cs b/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanActivityLogTask.cs
index 4abbf784b..50ba9bc89 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanActivityLogTask.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanActivityLogTask.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
@@ -75,4 +75,4 @@ namespace Emby.Server.Implementations.ScheduledTasks.Tasks
             return Enumerable.Empty<TaskTriggerInfo>();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/Emby.Server.Implementations/ScheduledTasks/Tasks/OptimizeDatabaseTask.cs b/Emby.Server.Implementations/ScheduledTasks/Tasks/OptimizeDatabaseTask.cs
new file mode 100644
index 000000000..1ad1d0f50
--- /dev/null
+++ b/Emby.Server.Implementations/ScheduledTasks/Tasks/OptimizeDatabaseTask.cs
@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Server.Implementations;
+using MediaBrowser.Model.Globalization;
+using MediaBrowser.Model.Tasks;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Emby.Server.Implementations.ScheduledTasks.Tasks
+{
+    /// <summary>
+    /// Optimizes Jellyfin's database by issuing a VACUUM command.
+    /// </summary>
+    public class OptimizeDatabaseTask : IScheduledTask, IConfigurableScheduledTask
+    {
+        private readonly ILogger<OptimizeDatabaseTask> _logger;
+        private readonly ILocalizationManager _localization;
+        private readonly JellyfinDbProvider _provider;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="OptimizeDatabaseTask" /> class.
+        /// </summary>
+        public OptimizeDatabaseTask(
+            ILogger<OptimizeDatabaseTask> logger,
+            ILocalizationManager localization,
+            JellyfinDbProvider provider)
+        {
+            _logger = logger;
+            _localization = localization;
+            _provider = provider;
+        }
+
+        /// <inheritdoc />
+        public string Name => _localization.GetLocalizedString("TaskOptimizeDatabase");
+
+        /// <inheritdoc />
+        public string Description => _localization.GetLocalizedString("TaskOptimizeDatabaseDescription");
+
+        /// <inheritdoc />
+        public string Category => _localization.GetLocalizedString("TasksMaintenanceCategory");
+
+        /// <inheritdoc />
+        public string Key => "OptimizeDatabaseTask";
+
+        /// <inheritdoc />
+        public bool IsHidden => false;
+
+        /// <inheritdoc />
+        public bool IsEnabled => true;
+
+        /// <inheritdoc />
+        public bool IsLogged => true;
+
+        /// <summary>
+        /// Creates the triggers that define when the task will run.
+        /// </summary>
+        /// <returns>IEnumerable{BaseTaskTrigger}.</returns>
+        public IEnumerable<TaskTriggerInfo> GetDefaultTriggers()
+        {
+            return new[]
+            {
+                // Every so often
+                new TaskTriggerInfo { Type = TaskTriggerInfo.TriggerInterval, IntervalTicks = TimeSpan.FromHours(24).Ticks }
+            };
+        }
+
+        /// <summary>
+        /// Returns the task to be executed.
+        /// </summary>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <param name="progress">The progress.</param>
+        /// <returns>Task.</returns>
+        public Task Execute(CancellationToken cancellationToken, IProgress<double> progress)
+        {
+            _logger.LogInformation("Optimizing and vacuuming jellyfin.db...");
+
+            try
+            {
+                using var context = _provider.CreateContext();
+                if (context.Database.IsSqlite())
+                {
+                    context.Database.ExecuteSqlRaw("PRAGMA optimize");
+                    context.Database.ExecuteSqlRaw("VACUUM");
+                    _logger.LogInformation("jellyfin.db optimized successfully!");
+                }
+                else
+                {
+                    _logger.LogInformation("This database doesn't support optimization");
+                }
+            }
+            catch (Exception e)
+            {
+                _logger.LogError(e, "Error while optimizing jellyfin.db");
+            }
+
+            return Task.CompletedTask;
+        }
+    }
+}
diff --git a/Emby.Server.Implementations/ScheduledTasks/Triggers/DailyTrigger.cs b/Emby.Server.Implementations/ScheduledTasks/Triggers/DailyTrigger.cs
index 3b40320ab..29ab6a73d 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Triggers/DailyTrigger.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Triggers/DailyTrigger.cs
@@ -8,29 +8,31 @@ namespace Emby.Server.Implementations.ScheduledTasks
     /// <summary>
     /// Represents a task trigger that fires everyday.
     /// </summary>
-    public class DailyTrigger : ITaskTrigger
+    public sealed class DailyTrigger : ITaskTrigger
     {
-        /// <summary>
-        /// Occurs when [triggered].
-        /// </summary>
-        public event EventHandler<EventArgs> Triggered;
+        private readonly TimeSpan _timeOfDay;
+        private Timer? _timer;
 
         /// <summary>
-        /// Gets or sets the time of day to trigger the task to run.
+        /// Initializes a new instance of the <see cref="DailyTrigger"/> class.
         /// </summary>
-        /// <value>The time of day.</value>
-        public TimeSpan TimeOfDay { get; set; }
+        /// <param name="timeofDay">The time of day to trigger the task to run.</param>
+        /// <param name="taskOptions">The options of this task.</param>
+        public DailyTrigger(TimeSpan timeofDay, TaskOptions taskOptions)
+        {
+            _timeOfDay = timeofDay;
+            TaskOptions = taskOptions;
+        }
 
         /// <summary>
-        /// Gets or sets the options of this task.
+        /// Occurs when [triggered].
         /// </summary>
-        public TaskOptions TaskOptions { get; set; }
+        public event EventHandler<EventArgs>? Triggered;
 
         /// <summary>
-        /// Gets or sets the timer.
+        /// Gets the options of this task.
         /// </summary>
-        /// <value>The timer.</value>
-        private Timer Timer { get; set; }
+        public TaskOptions TaskOptions { get; }
 
         /// <summary>
         /// Stars waiting for the trigger action.
@@ -45,14 +47,14 @@ namespace Emby.Server.Implementations.ScheduledTasks
 
             var now = DateTime.Now;
 
-            var triggerDate = now.TimeOfDay > TimeOfDay ? now.Date.AddDays(1) : now.Date;
-            triggerDate = triggerDate.Add(TimeOfDay);
+            var triggerDate = now.TimeOfDay > _timeOfDay ? now.Date.AddDays(1) : now.Date;
+            triggerDate = triggerDate.Add(_timeOfDay);
 
             var dueTime = triggerDate - now;
 
             logger.LogInformation("Daily trigger for {Task} set to fire at {TriggerDate:yyyy-MM-dd HH:mm:ss.fff zzz}, which is {DueTime:c} from now.", taskName, triggerDate, dueTime);
 
-            Timer = new Timer(state => OnTriggered(), null, dueTime, TimeSpan.FromMilliseconds(-1));
+            _timer = new Timer(state => OnTriggered(), null, dueTime, TimeSpan.FromMilliseconds(-1));
         }
 
         /// <summary>
@@ -68,10 +70,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
         /// </summary>
         private void DisposeTimer()
         {
-            if (Timer != null)
-            {
-                Timer.Dispose();
-            }
+            _timer?.Dispose();
         }
 
         /// <summary>
diff --git a/Emby.Server.Implementations/ScheduledTasks/Triggers/IntervalTrigger.cs b/Emby.Server.Implementations/ScheduledTasks/Triggers/IntervalTrigger.cs
index b04fd7c7e..30568e809 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Triggers/IntervalTrigger.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Triggers/IntervalTrigger.cs
@@ -9,31 +9,32 @@ namespace Emby.Server.Implementations.ScheduledTasks
     /// <summary>
     /// Represents a task trigger that runs repeatedly on an interval.
     /// </summary>
-    public class IntervalTrigger : ITaskTrigger
+    public sealed class IntervalTrigger : ITaskTrigger
     {
+        private readonly TimeSpan _interval;
         private DateTime _lastStartDate;
+        private Timer? _timer;
 
         /// <summary>
-        /// Occurs when [triggered].
+        /// Initializes a new instance of the <see cref="IntervalTrigger"/> class.
         /// </summary>
-        public event EventHandler<EventArgs> Triggered;
-
-        /// <summary>
-        /// Gets or sets the interval.
-        /// </summary>
-        /// <value>The interval.</value>
-        public TimeSpan Interval { get; set; }
+        /// <param name="interval">The interval.</param>
+        /// <param name="taskOptions">The options of this task.</param>
+        public IntervalTrigger(TimeSpan interval, TaskOptions taskOptions)
+        {
+            _interval = interval;
+            TaskOptions = taskOptions;
+        }
 
         /// <summary>
-        /// Gets or sets the options of this task.
+        /// Occurs when [triggered].
         /// </summary>
-        public TaskOptions TaskOptions { get; set; }
+        public event EventHandler<EventArgs>? Triggered;
 
         /// <summary>
-        /// Gets or sets the timer.
+        /// Gets the options of this task.
         /// </summary>
-        /// <value>The timer.</value>
-        private Timer Timer { get; set; }
+        public TaskOptions TaskOptions { get; }
 
         /// <summary>
         /// Stars waiting for the trigger action.
@@ -55,7 +56,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
             }
             else
             {
-                triggerDate = new[] { lastResult.EndTimeUtc, _lastStartDate }.Max().Add(Interval);
+                triggerDate = new[] { lastResult.EndTimeUtc, _lastStartDate }.Max().Add(_interval);
             }
 
             if (DateTime.UtcNow > triggerDate)
@@ -71,7 +72,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
                 dueTime = maxDueTime;
             }
 
-            Timer = new Timer(state => OnTriggered(), null, dueTime, TimeSpan.FromMilliseconds(-1));
+            _timer = new Timer(state => OnTriggered(), null, dueTime, TimeSpan.FromMilliseconds(-1));
         }
 
         /// <summary>
@@ -87,10 +88,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
         /// </summary>
         private void DisposeTimer()
         {
-            if (Timer != null)
-            {
-                Timer.Dispose();
-            }
+            _timer?.Dispose();
         }
 
         /// <summary>
diff --git a/Emby.Server.Implementations/ScheduledTasks/Triggers/StartupTrigger.cs b/Emby.Server.Implementations/ScheduledTasks/Triggers/StartupTrigger.cs
index 7cd5493da..18b9a8b75 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Triggers/StartupTrigger.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Triggers/StartupTrigger.cs
@@ -10,24 +10,28 @@ namespace Emby.Server.Implementations.ScheduledTasks
     /// <summary>
     /// Class StartupTaskTrigger.
     /// </summary>
-    public class StartupTrigger : ITaskTrigger
+    public sealed class StartupTrigger : ITaskTrigger
     {
+        public const int DelayMs = 3000;
+
         /// <summary>
-        /// Occurs when [triggered].
+        /// Initializes a new instance of the <see cref="StartupTrigger"/> class.
         /// </summary>
-        public event EventHandler<EventArgs> Triggered;
-
-        public int DelayMs { get; set; }
+        /// <param name="taskOptions">The options of this task.</param>
+        public StartupTrigger(TaskOptions taskOptions)
+        {
+            TaskOptions = taskOptions;
+        }
 
         /// <summary>
-        /// Gets or sets the options of this task.
+        /// Occurs when [triggered].
         /// </summary>
-        public TaskOptions TaskOptions { get; set; }
+        public event EventHandler<EventArgs>? Triggered;
 
-        public StartupTrigger()
-        {
-            DelayMs = 3000;
-        }
+        /// <summary>
+        /// Gets the options of this task.
+        /// </summary>
+        public TaskOptions TaskOptions { get; }
 
         /// <summary>
         /// Stars waiting for the trigger action.
diff --git a/Emby.Server.Implementations/ScheduledTasks/Triggers/WeeklyTrigger.cs b/Emby.Server.Implementations/ScheduledTasks/Triggers/WeeklyTrigger.cs
index 0c0ebec08..36ae190b0 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Triggers/WeeklyTrigger.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Triggers/WeeklyTrigger.cs
@@ -8,35 +8,34 @@ namespace Emby.Server.Implementations.ScheduledTasks
     /// <summary>
     /// Represents a task trigger that fires on a weekly basis.
     /// </summary>
-    public class WeeklyTrigger : ITaskTrigger
+    public sealed class WeeklyTrigger : ITaskTrigger
     {
-        /// <summary>
-        /// Occurs when [triggered].
-        /// </summary>
-        public event EventHandler<EventArgs> Triggered;
-
-        /// <summary>
-        /// Gets or sets the time of day to trigger the task to run.
-        /// </summary>
-        /// <value>The time of day.</value>
-        public TimeSpan TimeOfDay { get; set; }
+        private readonly TimeSpan _timeOfDay;
+        private readonly DayOfWeek _dayOfWeek;
+        private Timer? _timer;
 
         /// <summary>
-        /// Gets or sets the day of week.
+        /// Initializes a new instance of the <see cref="WeeklyTrigger"/> class.
         /// </summary>
-        /// <value>The day of week.</value>
-        public DayOfWeek DayOfWeek { get; set; }
+        /// <param name="timeofDay">The time of day to trigger the task to run.</param>
+        /// <param name="dayOfWeek">The day of week.</param>
+        /// <param name="taskOptions">The options of this task.</param>
+        public WeeklyTrigger(TimeSpan timeofDay, DayOfWeek dayOfWeek, TaskOptions taskOptions)
+        {
+            _timeOfDay = timeofDay;
+            _dayOfWeek = dayOfWeek;
+            TaskOptions = taskOptions;
+        }
 
         /// <summary>
-        /// Gets or sets the options of this task.
+        /// Occurs when [triggered].
         /// </summary>
-        public TaskOptions TaskOptions { get; set; }
+        public event EventHandler<EventArgs>? Triggered;
 
         /// <summary>
-        /// Gets or sets the timer.
+        /// Gets the options of this task.
         /// </summary>
-        /// <value>The timer.</value>
-        private Timer Timer { get; set; }
+        public TaskOptions TaskOptions { get; }
 
         /// <summary>
         /// Stars waiting for the trigger action.
@@ -51,7 +50,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
 
             var triggerDate = GetNextTriggerDateTime();
 
-            Timer = new Timer(state => OnTriggered(), null, triggerDate - DateTime.Now, TimeSpan.FromMilliseconds(-1));
+            _timer = new Timer(state => OnTriggered(), null, triggerDate - DateTime.Now, TimeSpan.FromMilliseconds(-1));
         }
 
         /// <summary>
@@ -63,22 +62,22 @@ namespace Emby.Server.Implementations.ScheduledTasks
             var now = DateTime.Now;
 
             // If it's on the same day
-            if (now.DayOfWeek == DayOfWeek)
+            if (now.DayOfWeek == _dayOfWeek)
             {
                 // It's either later today, or a week from now
-                return now.TimeOfDay < TimeOfDay ? now.Date.Add(TimeOfDay) : now.Date.AddDays(7).Add(TimeOfDay);
+                return now.TimeOfDay < _timeOfDay ? now.Date.Add(_timeOfDay) : now.Date.AddDays(7).Add(_timeOfDay);
             }
 
             var triggerDate = now.Date;
 
             // Walk the date forward until we get to the trigger day
-            while (triggerDate.DayOfWeek != DayOfWeek)
+            while (triggerDate.DayOfWeek != _dayOfWeek)
             {
                 triggerDate = triggerDate.AddDays(1);
             }
 
             // Return the trigger date plus the time offset
-            return triggerDate.Add(TimeOfDay);
+            return triggerDate.Add(_timeOfDay);
         }
 
         /// <summary>
@@ -94,10 +93,7 @@ namespace Emby.Server.Implementations.ScheduledTasks
         /// </summary>
         private void DisposeTimer()
         {
-            if (Timer != null)
-            {
-                Timer.Dispose();
-            }
+            _timer?.Dispose();
         }
 
         /// <summary>
diff --git a/Emby.Server.Implementations/Serialization/MyXmlSerializer.cs b/Emby.Server.Implementations/Serialization/MyXmlSerializer.cs
index 27024e4e1..5ff73de81 100644
--- a/Emby.Server.Implementations/Serialization/MyXmlSerializer.cs
+++ b/Emby.Server.Implementations/Serialization/MyXmlSerializer.cs
@@ -19,7 +19,10 @@ namespace Emby.Server.Implementations.Serialization
             new ConcurrentDictionary<string, XmlSerializer>();
 
         private static XmlSerializer GetSerializer(Type type)
-            => _serializers.GetOrAdd(type.FullName, _ => new XmlSerializer(type));
+            => _serializers.GetOrAdd(
+                type.FullName ?? throw new ArgumentException($"Invalid type {type}."),
+                (_, t) => new XmlSerializer(t),
+                type);
 
         /// <summary>
         /// Serializes to writer.
@@ -38,7 +41,7 @@ namespace Emby.Server.Implementations.Serialization
         /// <param name="type">The type.</param>
         /// <param name="stream">The stream.</param>
         /// <returns>System.Object.</returns>
-        public object DeserializeFromStream(Type type, Stream stream)
+        public object? DeserializeFromStream(Type type, Stream stream)
         {
             using (var reader = XmlReader.Create(stream))
             {
@@ -81,7 +84,7 @@ namespace Emby.Server.Implementations.Serialization
         /// <param name="type">The type.</param>
         /// <param name="file">The file.</param>
         /// <returns>System.Object.</returns>
-        public object DeserializeFromFile(Type type, string file)
+        public object? DeserializeFromFile(Type type, string file)
         {
             using (var stream = File.OpenRead(file))
             {
@@ -95,7 +98,7 @@ namespace Emby.Server.Implementations.Serialization
         /// <param name="type">The type.</param>
         /// <param name="buffer">The buffer.</param>
         /// <returns>System.Object.</returns>
-        public object DeserializeFromBytes(Type type, byte[] buffer)
+        public object? DeserializeFromBytes(Type type, byte[] buffer)
         {
             using (var stream = new MemoryStream(buffer, 0, buffer.Length, false, true))
             {
diff --git a/Emby.Server.Implementations/ServerApplicationPaths.cs b/Emby.Server.Implementations/ServerApplicationPaths.cs
index ac589b03c..6cf9a8f71 100644
--- a/Emby.Server.Implementations/ServerApplicationPaths.cs
+++ b/Emby.Server.Implementations/ServerApplicationPaths.cs
@@ -25,6 +25,10 @@ namespace Emby.Server.Implementations
                 cacheDirectoryPath,
                 webDirectoryPath)
         {
+            // ProgramDataPath cannot change when the server is running, so cache these to avoid allocations.
+            RootFolderPath = Path.Join(ProgramDataPath, "root");
+            DefaultUserViewsPath = Path.Combine(RootFolderPath, "default");
+            DefaultInternalMetadataPath = Path.Combine(ProgramDataPath, "metadata");
             InternalMetadataPath = DefaultInternalMetadataPath;
         }
 
@@ -32,13 +36,13 @@ namespace Emby.Server.Implementations
         /// Gets the path to the base root media directory.
         /// </summary>
         /// <value>The root folder path.</value>
-        public string RootFolderPath => Path.Combine(ProgramDataPath, "root");
+        public string RootFolderPath { get; }
 
         /// <summary>
         /// Gets the path to the default user view directory.  Used if no specific user view is defined.
         /// </summary>
         /// <value>The default user views path.</value>
-        public string DefaultUserViewsPath => Path.Combine(RootFolderPath, "default");
+        public string DefaultUserViewsPath { get; }
 
         /// <summary>
         /// Gets the path to the People directory.
@@ -98,7 +102,7 @@ namespace Emby.Server.Implementations
         public string UserConfigurationDirectoryPath => Path.Combine(ConfigurationDirectoryPath, "users");
 
         /// <inheritdoc/>
-        public string DefaultInternalMetadataPath => Path.Combine(ProgramDataPath, "metadata");
+        public string DefaultInternalMetadataPath { get; }
 
         /// <inheritdoc />
         public string InternalMetadataPath { get; set; }
diff --git a/Emby.Server.Implementations/Session/SessionManager.cs b/Emby.Server.Implementations/Session/SessionManager.cs
index b8c778690..544c8e5fd 100644
--- a/Emby.Server.Implementations/Session/SessionManager.cs
+++ b/Emby.Server.Implementations/Session/SessionManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Session/SessionWebSocketListener.cs b/Emby.Server.Implementations/Session/SessionWebSocketListener.cs
index 54e64cfeb..2a14a8c7b 100644
--- a/Emby.Server.Implementations/Session/SessionWebSocketListener.cs
+++ b/Emby.Server.Implementations/Session/SessionWebSocketListener.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/Emby.Server.Implementations/Session/WebSocketController.cs b/Emby.Server.Implementations/Session/WebSocketController.cs
index a653b58c2..9fa92a53a 100644
--- a/Emby.Server.Implementations/Session/WebSocketController.cs
+++ b/Emby.Server.Implementations/Session/WebSocketController.cs
@@ -1,6 +1,4 @@
 #pragma warning disable CS1591
-#pragma warning disable SA1600
-#nullable enable
 
 using System;
 using System.Collections.Generic;
diff --git a/Emby.Server.Implementations/Sorting/AiredEpisodeOrderComparer.cs b/Emby.Server.Implementations/Sorting/AiredEpisodeOrderComparer.cs
index 60698e803..2b0ab536f 100644
--- a/Emby.Server.Implementations/Sorting/AiredEpisodeOrderComparer.cs
+++ b/Emby.Server.Implementations/Sorting/AiredEpisodeOrderComparer.cs
@@ -16,7 +16,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             if (x == null)
             {
diff --git a/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs b/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs
index 7657cc74e..42e644970 100644
--- a/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs
+++ b/Emby.Server.Implementations/Sorting/AlbumArtistComparer.cs
@@ -18,7 +18,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return string.Compare(GetValue(x), GetValue(y), StringComparison.CurrentCultureIgnoreCase);
         }
@@ -28,7 +28,7 @@ namespace Emby.Server.Implementations.Sorting
         /// </summary>
         /// <param name="x">The x.</param>
         /// <returns>System.String.</returns>
-        private static string GetValue(BaseItem x)
+        private static string? GetValue(BaseItem? x)
         {
             var audio = x as IHasAlbumArtist;
 
diff --git a/Emby.Server.Implementations/Sorting/AlbumComparer.cs b/Emby.Server.Implementations/Sorting/AlbumComparer.cs
index 7dfdd9ecf..1db3f5e9c 100644
--- a/Emby.Server.Implementations/Sorting/AlbumComparer.cs
+++ b/Emby.Server.Implementations/Sorting/AlbumComparer.cs
@@ -17,7 +17,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return string.Compare(GetValue(x), GetValue(y), StringComparison.CurrentCultureIgnoreCase);
         }
@@ -27,7 +27,7 @@ namespace Emby.Server.Implementations.Sorting
         /// </summary>
         /// <param name="x">The x.</param>
         /// <returns>System.String.</returns>
-        private static string GetValue(BaseItem x)
+        private static string? GetValue(BaseItem? x)
         {
             var audio = x as Audio;
 
diff --git a/Emby.Server.Implementations/Sorting/ArtistComparer.cs b/Emby.Server.Implementations/Sorting/ArtistComparer.cs
index 756d3c5b6..98bee3fd9 100644
--- a/Emby.Server.Implementations/Sorting/ArtistComparer.cs
+++ b/Emby.Server.Implementations/Sorting/ArtistComparer.cs
@@ -15,7 +15,7 @@ namespace Emby.Server.Implementations.Sorting
         public string Name => ItemSortBy.Artist;
 
         /// <inheritdoc />
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return string.Compare(GetValue(x), GetValue(y), StringComparison.CurrentCultureIgnoreCase);
         }
@@ -25,7 +25,7 @@ namespace Emby.Server.Implementations.Sorting
         /// </summary>
         /// <param name="x">The x.</param>
         /// <returns>System.String.</returns>
-        private static string GetValue(BaseItem x)
+        private static string? GetValue(BaseItem? x)
         {
             if (!(x is Audio audio))
             {
diff --git a/Emby.Server.Implementations/Sorting/CommunityRatingComparer.cs b/Emby.Server.Implementations/Sorting/CommunityRatingComparer.cs
index 980954ba0..5f142fa4b 100644
--- a/Emby.Server.Implementations/Sorting/CommunityRatingComparer.cs
+++ b/Emby.Server.Implementations/Sorting/CommunityRatingComparer.cs
@@ -21,7 +21,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             if (x == null)
             {
diff --git a/Emby.Server.Implementations/Sorting/CriticRatingComparer.cs b/Emby.Server.Implementations/Sorting/CriticRatingComparer.cs
index fa136c36d..d20dedc2d 100644
--- a/Emby.Server.Implementations/Sorting/CriticRatingComparer.cs
+++ b/Emby.Server.Implementations/Sorting/CriticRatingComparer.cs
@@ -15,14 +15,14 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return GetValue(x).CompareTo(GetValue(y));
         }
 
-        private static float GetValue(BaseItem x)
+        private static float GetValue(BaseItem? x)
         {
-            return x.CriticRating ?? 0;
+            return x?.CriticRating ?? 0;
         }
 
         /// <summary>
diff --git a/Emby.Server.Implementations/Sorting/DateCreatedComparer.cs b/Emby.Server.Implementations/Sorting/DateCreatedComparer.cs
index cbca300d2..d3f10f78c 100644
--- a/Emby.Server.Implementations/Sorting/DateCreatedComparer.cs
+++ b/Emby.Server.Implementations/Sorting/DateCreatedComparer.cs
@@ -16,7 +16,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             if (x == null)
             {
diff --git a/Emby.Server.Implementations/Sorting/DateLastMediaAddedComparer.cs b/Emby.Server.Implementations/Sorting/DateLastMediaAddedComparer.cs
index 03ff19d21..b1cb123ce 100644
--- a/Emby.Server.Implementations/Sorting/DateLastMediaAddedComparer.cs
+++ b/Emby.Server.Implementations/Sorting/DateLastMediaAddedComparer.cs
@@ -1,3 +1,4 @@
+#nullable disable
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Sorting/DatePlayedComparer.cs b/Emby.Server.Implementations/Sorting/DatePlayedComparer.cs
index 16bd2aff8..08a44319f 100644
--- a/Emby.Server.Implementations/Sorting/DatePlayedComparer.cs
+++ b/Emby.Server.Implementations/Sorting/DatePlayedComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using Jellyfin.Data.Entities;
 using MediaBrowser.Controller.Entities;
diff --git a/Emby.Server.Implementations/Sorting/IsFavoriteOrLikeComparer.cs b/Emby.Server.Implementations/Sorting/IsFavoriteOrLikeComparer.cs
index 0c4e82d01..73e628cf7 100644
--- a/Emby.Server.Implementations/Sorting/IsFavoriteOrLikeComparer.cs
+++ b/Emby.Server.Implementations/Sorting/IsFavoriteOrLikeComparer.cs
@@ -1,3 +1,4 @@
+#nullable disable
 #pragma warning disable CS1591
 
 using Jellyfin.Data.Entities;
diff --git a/Emby.Server.Implementations/Sorting/IsFolderComparer.cs b/Emby.Server.Implementations/Sorting/IsFolderComparer.cs
index a35192eff..3c5ddeefa 100644
--- a/Emby.Server.Implementations/Sorting/IsFolderComparer.cs
+++ b/Emby.Server.Implementations/Sorting/IsFolderComparer.cs
@@ -20,7 +20,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return GetValue(x).CompareTo(GetValue(y));
         }
@@ -30,9 +30,9 @@ namespace Emby.Server.Implementations.Sorting
         /// </summary>
         /// <param name="x">The x.</param>
         /// <returns>System.String.</returns>
-        private static int GetValue(BaseItem x)
+        private static int GetValue(BaseItem? x)
         {
-            return x.IsFolder ? 0 : 1;
+            return x?.IsFolder ?? true ? 0 : 1;
         }
     }
 }
diff --git a/Emby.Server.Implementations/Sorting/IsPlayedComparer.cs b/Emby.Server.Implementations/Sorting/IsPlayedComparer.cs
index d95948406..7d77a8bc5 100644
--- a/Emby.Server.Implementations/Sorting/IsPlayedComparer.cs
+++ b/Emby.Server.Implementations/Sorting/IsPlayedComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using Jellyfin.Data.Entities;
diff --git a/Emby.Server.Implementations/Sorting/IsUnplayedComparer.cs b/Emby.Server.Implementations/Sorting/IsUnplayedComparer.cs
index 1632c5a7a..926835f90 100644
--- a/Emby.Server.Implementations/Sorting/IsUnplayedComparer.cs
+++ b/Emby.Server.Implementations/Sorting/IsUnplayedComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using Jellyfin.Data.Entities;
diff --git a/Emby.Server.Implementations/Sorting/NameComparer.cs b/Emby.Server.Implementations/Sorting/NameComparer.cs
index da020d8d8..4de81a69e 100644
--- a/Emby.Server.Implementations/Sorting/NameComparer.cs
+++ b/Emby.Server.Implementations/Sorting/NameComparer.cs
@@ -16,7 +16,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             if (x == null)
             {
diff --git a/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs b/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs
index 76bb798b5..a81f78ebf 100644
--- a/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs
+++ b/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs
@@ -29,7 +29,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             if (x == null)
             {
diff --git a/Emby.Server.Implementations/Sorting/PlayCountComparer.cs b/Emby.Server.Implementations/Sorting/PlayCountComparer.cs
index 5c2830322..04e4865cb 100644
--- a/Emby.Server.Implementations/Sorting/PlayCountComparer.cs
+++ b/Emby.Server.Implementations/Sorting/PlayCountComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using Jellyfin.Data.Entities;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
diff --git a/Emby.Server.Implementations/Sorting/PremiereDateComparer.cs b/Emby.Server.Implementations/Sorting/PremiereDateComparer.cs
index 92ac04dc6..c98f97bf1 100644
--- a/Emby.Server.Implementations/Sorting/PremiereDateComparer.cs
+++ b/Emby.Server.Implementations/Sorting/PremiereDateComparer.cs
@@ -16,7 +16,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return GetDate(x).CompareTo(GetDate(y));
         }
@@ -26,8 +26,13 @@ namespace Emby.Server.Implementations.Sorting
         /// </summary>
         /// <param name="x">The x.</param>
         /// <returns>DateTime.</returns>
-        private static DateTime GetDate(BaseItem x)
+        private static DateTime GetDate(BaseItem? x)
         {
+            if (x == null)
+            {
+                return DateTime.MinValue;
+            }
+
             if (x.PremiereDate.HasValue)
             {
                 return x.PremiereDate.Value;
diff --git a/Emby.Server.Implementations/Sorting/ProductionYearComparer.cs b/Emby.Server.Implementations/Sorting/ProductionYearComparer.cs
index e2857df0b..df9f9957d 100644
--- a/Emby.Server.Implementations/Sorting/ProductionYearComparer.cs
+++ b/Emby.Server.Implementations/Sorting/ProductionYearComparer.cs
@@ -15,7 +15,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return GetValue(x).CompareTo(GetValue(y));
         }
@@ -25,8 +25,13 @@ namespace Emby.Server.Implementations.Sorting
         /// </summary>
         /// <param name="x">The x.</param>
         /// <returns>DateTime.</returns>
-        private static int GetValue(BaseItem x)
+        private static int GetValue(BaseItem? x)
         {
+            if (x == null)
+            {
+                return 0;
+            }
+
             if (x.ProductionYear.HasValue)
             {
                 return x.ProductionYear.Value;
diff --git a/Emby.Server.Implementations/Sorting/RandomComparer.cs b/Emby.Server.Implementations/Sorting/RandomComparer.cs
index 7739d0418..af3bc2750 100644
--- a/Emby.Server.Implementations/Sorting/RandomComparer.cs
+++ b/Emby.Server.Implementations/Sorting/RandomComparer.cs
@@ -16,7 +16,7 @@ namespace Emby.Server.Implementations.Sorting
         /// <param name="x">The x.</param>
         /// <param name="y">The y.</param>
         /// <returns>System.Int32.</returns>
-        public int Compare(BaseItem x, BaseItem y)
+        public int Compare(BaseItem? x, BaseItem? y)
         {
             return Guid.NewGuid().CompareTo(Guid.NewGuid());
         }
diff --git a/Emby.Server.Implementations/Sorting/RuntimeComparer.cs b/Emby.Server.Implementations/Sorting/RuntimeComparer.cs
index dde44333d..129315303 100644
--- a/Emby.Server.Implementations/Sorting/RuntimeComparer.cs
+++ b/Emby.Server.Implementations/Sorting/RuntimeComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Sorting;
diff --git a/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs b/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs
index b9205ee07..4123a59f8 100644
--- a/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs
+++ b/Emby.Server.Implementations/Sorting/SeriesSortNameComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Sorting/SortNameComparer.cs b/Emby.Server.Implementations/Sorting/SortNameComparer.cs
index f745e193b..8d30716d3 100644
--- a/Emby.Server.Implementations/Sorting/SortNameComparer.cs
+++ b/Emby.Server.Implementations/Sorting/SortNameComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Sorting;
diff --git a/Emby.Server.Implementations/Sorting/StartDateComparer.cs b/Emby.Server.Implementations/Sorting/StartDateComparer.cs
index 558a3d351..c3df7c47e 100644
--- a/Emby.Server.Implementations/Sorting/StartDateComparer.cs
+++ b/Emby.Server.Implementations/Sorting/StartDateComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/Sorting/StudioComparer.cs b/Emby.Server.Implementations/Sorting/StudioComparer.cs
index 5766dc542..01445c525 100644
--- a/Emby.Server.Implementations/Sorting/StudioComparer.cs
+++ b/Emby.Server.Implementations/Sorting/StudioComparer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/Emby.Server.Implementations/SyncPlay/Group.cs b/Emby.Server.Implementations/SyncPlay/Group.cs
index 7c2ad2477..12efff261 100644
--- a/Emby.Server.Implementations/SyncPlay/Group.cs
+++ b/Emby.Server.Implementations/SyncPlay/Group.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
diff --git a/Emby.Server.Implementations/SyncPlay/SyncPlayManager.cs b/Emby.Server.Implementations/SyncPlay/SyncPlayManager.cs
index 72c0a838e..993456196 100644
--- a/Emby.Server.Implementations/SyncPlay/SyncPlayManager.cs
+++ b/Emby.Server.Implementations/SyncPlay/SyncPlayManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
diff --git a/Emby.Server.Implementations/TV/TVSeriesManager.cs b/Emby.Server.Implementations/TV/TVSeriesManager.cs
index 829df64bf..af453d148 100644
--- a/Emby.Server.Implementations/TV/TVSeriesManager.cs
+++ b/Emby.Server.Implementations/TV/TVSeriesManager.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -152,7 +154,7 @@ namespace Emby.Server.Implementations.TV
                         return i.Item1 != DateTime.MinValue;
                     }
 
-                    if (alwaysEnableFirstEpisode || i.Item1 != DateTime.MinValue)
+                    if (alwaysEnableFirstEpisode || (i.Item1 != DateTime.MinValue && i.Item1.Date >= request.NextUpDateCutoff))
                     {
                         anyFound = true;
                         return true;
diff --git a/Emby.Server.Implementations/Udp/UdpServer.cs b/Emby.Server.Implementations/Udp/UdpServer.cs
index db5265e79..8179e26c5 100644
--- a/Emby.Server.Implementations/Udp/UdpServer.cs
+++ b/Emby.Server.Implementations/Udp/UdpServer.cs
@@ -18,17 +18,17 @@ namespace Emby.Server.Implementations.Udp
     public sealed class UdpServer : IDisposable
     {
         /// <summary>
+        /// Address Override Configuration Key.
+        /// </summary>
+        public const string AddressOverrideConfigKey = "PublishedServerUrl";
+
+        /// <summary>
         /// The _logger.
         /// </summary>
         private readonly ILogger _logger;
         private readonly IServerApplicationHost _appHost;
         private readonly IConfiguration _config;
 
-        /// <summary>
-        /// Address Override Configuration Key.
-        /// </summary>
-        public const string AddressOverrideConfigKey = "PublishedServerUrl";
-
         private Socket _udpSocket;
         private IPEndPoint _endpoint;
         private readonly byte[] _receiveBuffer = new byte[8192];
@@ -38,49 +38,58 @@ namespace Emby.Server.Implementations.Udp
         /// <summary>
         /// Initializes a new instance of the <see cref="UdpServer" /> class.
         /// </summary>
-        public UdpServer(ILogger logger, IServerApplicationHost appHost, IConfiguration configuration)
+        /// <param name="logger">The logger.</param>
+        /// <param name="appHost">The application host.</param>
+        /// <param name="configuration">The configuration manager.</param>
+        /// <param name="port">The port.</param>
+        public UdpServer(
+            ILogger logger,
+            IServerApplicationHost appHost,
+            IConfiguration configuration,
+            int port)
         {
             _logger = logger;
             _appHost = appHost;
             _config = configuration;
+
+            _endpoint = new IPEndPoint(IPAddress.Any, port);
+
+            _udpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
+            _udpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
         }
 
         private async Task RespondToV2Message(string messageText, EndPoint endpoint, CancellationToken cancellationToken)
         {
-            string localUrl = !string.IsNullOrEmpty(_config[AddressOverrideConfigKey])
-                ? _config[AddressOverrideConfigKey]
-                : _appHost.GetSmartApiUrl(((IPEndPoint)endpoint).Address);
+            string? localUrl = _config[AddressOverrideConfigKey];
+            if (string.IsNullOrEmpty(localUrl))
+            {
+                localUrl = _appHost.GetSmartApiUrl(((IPEndPoint)endpoint).Address);
+            }
 
-            if (!string.IsNullOrEmpty(localUrl))
+            if (string.IsNullOrEmpty(localUrl))
             {
-                var response = new ServerDiscoveryInfo(localUrl, _appHost.SystemId, _appHost.FriendlyName);
+                _logger.LogWarning("Unable to respond to udp request because the local ip address could not be determined.");
+                return;
+            }
 
-                try
-                {
-                    await _udpSocket.SendToAsync(JsonSerializer.SerializeToUtf8Bytes(response), SocketFlags.None, endpoint).ConfigureAwait(false);
-                }
-                catch (SocketException ex)
-                {
-                    _logger.LogError(ex, "Error sending response message");
-                }
+            var response = new ServerDiscoveryInfo(localUrl, _appHost.SystemId, _appHost.FriendlyName);
+
+            try
+            {
+                await _udpSocket.SendToAsync(JsonSerializer.SerializeToUtf8Bytes(response), SocketFlags.None, endpoint).ConfigureAwait(false);
             }
-            else
+            catch (SocketException ex)
             {
-                _logger.LogWarning("Unable to respond to udp request because the local ip address could not be determined.");
+                _logger.LogError(ex, "Error sending response message");
             }
         }
 
         /// <summary>
         /// Starts the specified port.
         /// </summary>
-        /// <param name="port">The port.</param>
         /// <param name="cancellationToken">The cancellation token to cancel operation.</param>
-        public void Start(int port, CancellationToken cancellationToken)
+        public void Start(CancellationToken cancellationToken)
         {
-            _endpoint = new IPEndPoint(IPAddress.Any, port);
-
-            _udpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
-            _udpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
             _udpSocket.Bind(_endpoint);
 
             _ = Task.Run(async () => await BeginReceiveAsync(cancellationToken).ConfigureAwait(false), cancellationToken).ConfigureAwait(false);
@@ -88,9 +97,9 @@ namespace Emby.Server.Implementations.Udp
 
         private async Task BeginReceiveAsync(CancellationToken cancellationToken)
         {
+            var infiniteTask = Task.Delay(-1, cancellationToken);
             while (!cancellationToken.IsCancellationRequested)
             {
-                var infiniteTask = Task.Delay(-1, cancellationToken);
                 try
                 {
                     var task = _udpSocket.ReceiveFromAsync(_receiveBuffer, SocketFlags.None, _endpoint);
diff --git a/Emby.Server.Implementations/Updates/InstallationManager.cs b/Emby.Server.Implementations/Updates/InstallationManager.cs
index 653b1381b..b0921cbd8 100644
--- a/Emby.Server.Implementations/Updates/InstallationManager.cs
+++ b/Emby.Server.Implementations/Updates/InstallationManager.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -101,12 +99,12 @@ namespace Emby.Server.Implementations.Updates
         public IEnumerable<InstallationInfo> CompletedInstallations => _completedInstallationsInternal;
 
         /// <inheritdoc />
-        public async Task<IList<PackageInfo>> GetPackages(string manifestName, string manifest, bool filterIncompatible, CancellationToken cancellationToken = default)
+        public async Task<PackageInfo[]> GetPackages(string manifestName, string manifest, bool filterIncompatible, CancellationToken cancellationToken = default)
         {
             try
             {
-                List<PackageInfo>? packages = await _httpClientFactory.CreateClient(NamedClient.Default)
-                        .GetFromJsonAsync<List<PackageInfo>>(new Uri(manifest), _jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
+                PackageInfo[]? packages = await _httpClientFactory.CreateClient(NamedClient.Default)
+                        .GetFromJsonAsync<PackageInfo[]>(new Uri(manifest), _jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
 
                 if (packages == null)
                 {
@@ -179,20 +177,14 @@ namespace Emby.Server.Implementations.Updates
                     // Where repositories have the same content, the details from the first is taken.
                     foreach (var package in await GetPackages(repository.Name ?? "Unnamed Repo", repository.Url, true, cancellationToken).ConfigureAwait(true))
                     {
-                        if (!Guid.TryParse(package.Id, out var packageGuid))
-                        {
-                            // Package doesn't have a valid GUID, skip.
-                            continue;
-                        }
-
-                        var existing = FilterPackages(result, package.Name, packageGuid).FirstOrDefault();
+                        var existing = FilterPackages(result, package.Name, package.Id).FirstOrDefault();
 
                         // Remove invalid versions from the valid package.
                         for (var i = package.Versions.Count - 1; i >= 0; i--)
                         {
                             var version = package.Versions[i];
 
-                            var plugin = _pluginManager.GetPlugin(packageGuid, version.VersionNumber);
+                            var plugin = _pluginManager.GetPlugin(package.Id, version.VersionNumber);
                             if (plugin != null)
                             {
                                 await _pluginManager.GenerateManifest(package, version.VersionNumber, plugin.Path, plugin.Manifest.Status).ConfigureAwait(false);
@@ -231,7 +223,7 @@ namespace Emby.Server.Implementations.Updates
         public IEnumerable<PackageInfo> FilterPackages(
             IEnumerable<PackageInfo> availablePackages,
             string? name = null,
-            Guid? id = default,
+            Guid id = default,
             Version? specificVersion = null)
         {
             if (name != null)
@@ -239,9 +231,9 @@ namespace Emby.Server.Implementations.Updates
                 availablePackages = availablePackages.Where(x => x.Name.Equals(name, StringComparison.OrdinalIgnoreCase));
             }
 
-            if (id != Guid.Empty)
+            if (id != default)
             {
-                availablePackages = availablePackages.Where(x => Guid.Parse(x.Id) == id);
+                availablePackages = availablePackages.Where(x => x.Id == id);
             }
 
             if (specificVersion != null)
@@ -256,7 +248,7 @@ namespace Emby.Server.Implementations.Updates
         public IEnumerable<InstallationInfo> GetCompatibleVersions(
             IEnumerable<PackageInfo> availablePackages,
             string? name = null,
-            Guid? id = default,
+            Guid id = default,
             Version? minVersion = null,
             Version? specificVersion = null)
         {
@@ -286,7 +278,7 @@ namespace Emby.Server.Implementations.Updates
                 yield return new InstallationInfo
                 {
                     Changelog = v.Changelog,
-                    Id = new Guid(package.Id),
+                    Id = package.Id,
                     Name = package.Name,
                     Version = v.VersionNumber,
                     SourceUrl = v.SourceUrl,