Merge pull request #5982 from Bond-009/nullable

44 files changed, 145 insertions, 165 deletions

diff --git a/Jellyfin.Api/Auth/BaseAuthorizationHandler.cs b/Jellyfin.Api/Auth/BaseAuthorizationHandler.cs
index 7d68aecf9..392498c53 100644
--- a/Jellyfin.Api/Auth/BaseAuthorizationHandler.cs
+++ b/Jellyfin.Api/Auth/BaseAuthorizationHandler.cs
@@ -77,8 +77,9 @@ namespace Jellyfin.Api.Auth
                 return false;
             }
 
-            var ip = _httpContextAccessor.HttpContext.GetNormalizedRemoteIp();
-            var isInLocalNetwork = _networkManager.IsInLocalNetwork(ip);
+            var isInLocalNetwork = _httpContextAccessor.HttpContext != null
+                && _networkManager.IsInLocalNetwork(_httpContextAccessor.HttpContext.GetNormalizedRemoteIp());
+
             // User cannot access remotely and user is remote
             if (!user.HasPermission(PermissionKind.EnableRemoteAccess) && !isInLocalNetwork)
             {
diff --git a/Jellyfin.Api/Controllers/ConfigurationController.cs b/Jellyfin.Api/Controllers/ConfigurationController.cs
index 049a4bed7..b6309baab 100644
--- a/Jellyfin.Api/Controllers/ConfigurationController.cs
+++ b/Jellyfin.Api/Controllers/ConfigurationController.cs
@@ -1,3 +1,4 @@
+using System;
 using System.ComponentModel.DataAnnotations;
 using System.Net.Mime;
 using System.Text.Json;
@@ -94,6 +95,11 @@ namespace Jellyfin.Api.Controllers
         {
             var configurationType = _configurationManager.GetConfigurationType(key);
             var configuration = await JsonSerializer.DeserializeAsync(Request.Body, configurationType, _serializerOptions).ConfigureAwait(false);
+            if (configuration == null)
+            {
+                throw new ArgumentException("Body doesn't contain a valid configuration");
+            }
+
             _configurationManager.SaveConfiguration(key, configuration);
             return NoContent();
         }
diff --git a/MediaBrowser.Common/Configuration/ConfigurationStore.cs b/MediaBrowser.Common/Configuration/ConfigurationStore.cs
index d31d45e4c..050ab1ab5 100644
--- a/MediaBrowser.Common/Configuration/ConfigurationStore.cs
+++ b/MediaBrowser.Common/Configuration/ConfigurationStore.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 
 namespace MediaBrowser.Common.Configuration
diff --git a/MediaBrowser.Common/Configuration/ConfigurationUpdateEventArgs.cs b/MediaBrowser.Common/Configuration/ConfigurationUpdateEventArgs.cs
index 344aecf53..2df87d879 100644
--- a/MediaBrowser.Common/Configuration/ConfigurationUpdateEventArgs.cs
+++ b/MediaBrowser.Common/Configuration/ConfigurationUpdateEventArgs.cs
@@ -1,3 +1,4 @@
+#nullable disable
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Common/Configuration/IApplicationPaths.cs b/MediaBrowser.Common/Configuration/IApplicationPaths.cs
index 57c654667..1370e6d79 100644
--- a/MediaBrowser.Common/Configuration/IApplicationPaths.cs
+++ b/MediaBrowser.Common/Configuration/IApplicationPaths.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace MediaBrowser.Common.Configuration
 {
     /// <summary>
diff --git a/MediaBrowser.Common/Cryptography/PasswordHash.cs b/MediaBrowser.Common/Cryptography/PasswordHash.cs
index ec21d0580..0e2065302 100644
--- a/MediaBrowser.Common/Cryptography/PasswordHash.cs
+++ b/MediaBrowser.Common/Cryptography/PasswordHash.cs
@@ -1,5 +1,4 @@
 #pragma warning disable CS1591
-#nullable enable
 
 using System;
 using System.Collections.Generic;
diff --git a/MediaBrowser.Common/Events/EventHelper.cs b/MediaBrowser.Common/Events/EventHelper.cs
index c9d3226ac..a9cf86fbc 100644
--- a/MediaBrowser.Common/Events/EventHelper.cs
+++ b/MediaBrowser.Common/Events/EventHelper.cs
@@ -17,7 +17,7 @@ namespace MediaBrowser.Common.Events
         /// <param name="sender">The sender.</param>
         /// <param name="args">The <see cref="EventArgs" /> instance containing the event data.</param>
         /// <param name="logger">The logger.</param>
-        public static void QueueEventIfNotNull(EventHandler handler, object sender, EventArgs args, ILogger logger)
+        public static void QueueEventIfNotNull(EventHandler? handler, object sender, EventArgs args, ILogger logger)
         {
             if (handler != null)
             {
@@ -43,7 +43,7 @@ namespace MediaBrowser.Common.Events
         /// <param name="sender">The sender.</param>
         /// <param name="args">The args.</param>
         /// <param name="logger">The logger.</param>
-        public static void QueueEventIfNotNull<T>(EventHandler<T> handler, object sender, T args, ILogger logger)
+        public static void QueueEventIfNotNull<T>(EventHandler<T>? handler, object sender, T args, ILogger logger)
         {
             if (handler != null)
             {
diff --git a/MediaBrowser.Common/Extensions/BaseExtensions.cs b/MediaBrowser.Common/Extensions/BaseExtensions.cs
index 40020093b..08964420e 100644
--- a/MediaBrowser.Common/Extensions/BaseExtensions.cs
+++ b/MediaBrowser.Common/Extensions/BaseExtensions.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Security.Cryptography;
 using System.Text;
diff --git a/MediaBrowser.Common/Extensions/CopyToExtensions.cs b/MediaBrowser.Common/Extensions/CopyToExtensions.cs
index 94bf7c740..2ecbc6539 100644
--- a/MediaBrowser.Common/Extensions/CopyToExtensions.cs
+++ b/MediaBrowser.Common/Extensions/CopyToExtensions.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System.Collections.Generic;
 
 namespace MediaBrowser.Common.Extensions
diff --git a/MediaBrowser.Common/Extensions/HttpContextExtensions.cs b/MediaBrowser.Common/Extensions/HttpContextExtensions.cs
index e51ad42d1..1e5877c84 100644
--- a/MediaBrowser.Common/Extensions/HttpContextExtensions.cs
+++ b/MediaBrowser.Common/Extensions/HttpContextExtensions.cs
@@ -17,7 +17,7 @@ namespace MediaBrowser.Common.Extensions
         {
             return (context.Connection.LocalIpAddress == null
                     && context.Connection.RemoteIpAddress == null)
-                   || context.Connection.LocalIpAddress.Equals(context.Connection.RemoteIpAddress);
+                   || Equals(context.Connection.LocalIpAddress, context.Connection.RemoteIpAddress);
         }
 
         /// <summary>
diff --git a/MediaBrowser.Common/Extensions/MethodNotAllowedException.cs b/MediaBrowser.Common/Extensions/MethodNotAllowedException.cs
index 258bd6662..48e758ee4 100644
--- a/MediaBrowser.Common/Extensions/MethodNotAllowedException.cs
+++ b/MediaBrowser.Common/Extensions/MethodNotAllowedException.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 
 namespace MediaBrowser.Common.Extensions
diff --git a/MediaBrowser.Common/Extensions/ProcessExtensions.cs b/MediaBrowser.Common/Extensions/ProcessExtensions.cs
index 2f52ba196..c74787122 100644
--- a/MediaBrowser.Common/Extensions/ProcessExtensions.cs
+++ b/MediaBrowser.Common/Extensions/ProcessExtensions.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Diagnostics;
 using System.Threading;
diff --git a/MediaBrowser.Common/Extensions/RateLimitExceededException.cs b/MediaBrowser.Common/Extensions/RateLimitExceededException.cs
index 7c7bdaa92..95802a462 100644
--- a/MediaBrowser.Common/Extensions/RateLimitExceededException.cs
+++ b/MediaBrowser.Common/Extensions/RateLimitExceededException.cs
@@ -1,4 +1,3 @@
-#nullable enable
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Common/Extensions/ResourceNotFoundException.cs b/MediaBrowser.Common/Extensions/ResourceNotFoundException.cs
index ebac9d8e6..22130c5a1 100644
--- a/MediaBrowser.Common/Extensions/ResourceNotFoundException.cs
+++ b/MediaBrowser.Common/Extensions/ResourceNotFoundException.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 
 namespace MediaBrowser.Common.Extensions
diff --git a/MediaBrowser.Common/Extensions/ShuffleExtensions.cs b/MediaBrowser.Common/Extensions/ShuffleExtensions.cs
index 6f0ea9bd5..2604abf85 100644
--- a/MediaBrowser.Common/Extensions/ShuffleExtensions.cs
+++ b/MediaBrowser.Common/Extensions/ShuffleExtensions.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Collections.Generic;
 
diff --git a/MediaBrowser.Common/Extensions/SplitStringExtensions.cs b/MediaBrowser.Common/Extensions/SplitStringExtensions.cs
index e78fa78d6..9c9108495 100644
--- a/MediaBrowser.Common/Extensions/SplitStringExtensions.cs
+++ b/MediaBrowser.Common/Extensions/SplitStringExtensions.cs
@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
  */
-#nullable enable
+
 #pragma warning disable CS1591
 #pragma warning disable CA1034
 using System;
diff --git a/MediaBrowser.Common/Extensions/StreamExtensions.cs b/MediaBrowser.Common/Extensions/StreamExtensions.cs
index d49bf1d46..5cbf57d98 100644
--- a/MediaBrowser.Common/Extensions/StreamExtensions.cs
+++ b/MediaBrowser.Common/Extensions/StreamExtensions.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
diff --git a/MediaBrowser.Common/IApplicationHost.cs b/MediaBrowser.Common/IApplicationHost.cs
index c3e4ed6db..46d93e494 100644
--- a/MediaBrowser.Common/IApplicationHost.cs
+++ b/MediaBrowser.Common/IApplicationHost.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Collections.Generic;
 using System.Reflection;
diff --git a/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverter.cs b/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverter.cs
index 2ec702165..127a41a06 100644
--- a/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverter.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverter.cs
@@ -9,67 +9,16 @@ namespace MediaBrowser.Common.Json.Converters
     /// Convert comma delimited string to array of type.
     /// </summary>
     /// <typeparam name="T">Type to convert to.</typeparam>
-    public class JsonCommaDelimitedArrayConverter<T> : JsonConverter<T[]>
+    public sealed class JsonCommaDelimitedArrayConverter<T> : JsonDelimitedArrayConverter<T>
     {
-        private readonly TypeConverter _typeConverter;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="JsonCommaDelimitedArrayConverter{T}"/> class.
         /// </summary>
-        public JsonCommaDelimitedArrayConverter()
+        public JsonCommaDelimitedArrayConverter() : base()
         {
-            _typeConverter = TypeDescriptor.GetConverter(typeof(T));
         }
 
         /// <inheritdoc />
-        public override T[] Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
-        {
-            if (reader.TokenType == JsonTokenType.String)
-            {
-                var stringEntries = reader.GetString().Split(',', StringSplitOptions.RemoveEmptyEntries);
-                if (stringEntries.Length == 0)
-                {
-                    return Array.Empty<T>();
-                }
-
-                var parsedValues = new object[stringEntries.Length];
-                var convertedCount = 0;
-                for (var i = 0; i < stringEntries.Length; i++)
-                {
-                    try
-                    {
-                        parsedValues[i] = _typeConverter.ConvertFrom(stringEntries[i].Trim());
-                        convertedCount++;
-                    }
-                    catch (FormatException)
-                    {
-                        // TODO log when upgraded to .Net6
-                        // https://github.com/dotnet/runtime/issues/42975
-                        // _logger.LogDebug(e, "Error converting value.");
-                    }
-                }
-
-                var typedValues = new T[convertedCount];
-                var typedValueIndex = 0;
-                for (var i = 0; i < stringEntries.Length; i++)
-                {
-                    if (parsedValues[i] != null)
-                    {
-                        typedValues.SetValue(parsedValues[i], typedValueIndex);
-                        typedValueIndex++;
-                    }
-                }
-
-                return typedValues;
-            }
-
-            return JsonSerializer.Deserialize<T[]>(ref reader, options);
-        }
-
-        /// <inheritdoc />
-        public override void Write(Utf8JsonWriter writer, T[] value, JsonSerializerOptions options)
-        {
-            throw new NotImplementedException();
-        }
+        protected override char Delimiter => ',';
     }
 }
diff --git a/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverterFactory.cs b/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverterFactory.cs
index 24ed3ea19..de41348dd 100644
--- a/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverterFactory.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonCommaDelimitedArrayConverterFactory.cs
@@ -19,10 +19,10 @@ namespace MediaBrowser.Common.Json.Converters
         }
 
         /// <inheritdoc />
-        public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+        public override JsonConverter? CreateConverter(Type typeToConvert, JsonSerializerOptions options)
         {
             var structType = typeToConvert.GetElementType() ?? typeToConvert.GenericTypeArguments[0];
-            return (JsonConverter)Activator.CreateInstance(typeof(JsonCommaDelimitedArrayConverter<>).MakeGenericType(structType));
+            return (JsonConverter?)Activator.CreateInstance(typeof(JsonCommaDelimitedArrayConverter<>).MakeGenericType(structType));
         }
     }
 }
diff --git a/MediaBrowser.Common/Json/Converters/JsonDelimitedArrayConverter.cs b/MediaBrowser.Common/Json/Converters/JsonDelimitedArrayConverter.cs
new file mode 100644
index 000000000..b691798c9
--- /dev/null
+++ b/MediaBrowser.Common/Json/Converters/JsonDelimitedArrayConverter.cs
@@ -0,0 +1,81 @@
+using System;
+using System.ComponentModel;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace MediaBrowser.Common.Json.Converters
+{
+    /// <summary>
+    /// Convert delimited string to array of type.
+    /// </summary>
+    /// <typeparam name="T">Type to convert to.</typeparam>
+    public abstract class JsonDelimitedArrayConverter<T> : JsonConverter<T[]?>
+    {
+        private readonly TypeConverter _typeConverter;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="JsonDelimitedArrayConverter{T}"/> class.
+        /// </summary>
+        protected JsonDelimitedArrayConverter()
+        {
+            _typeConverter = TypeDescriptor.GetConverter(typeof(T));
+        }
+
+        /// <summary>
+        /// Gets the array delimiter.
+        /// </summary>
+        protected virtual char Delimiter { get; }
+
+        /// <inheritdoc />
+        public override T[]? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            if (reader.TokenType == JsonTokenType.String)
+            {
+                // GetString can't return null here because we already handled it above
+                var stringEntries = reader.GetString()?.Split(Delimiter, StringSplitOptions.RemoveEmptyEntries);
+                if (stringEntries == null || stringEntries.Length == 0)
+                {
+                    return Array.Empty<T>();
+                }
+
+                var parsedValues = new object[stringEntries.Length];
+                var convertedCount = 0;
+                for (var i = 0; i < stringEntries.Length; i++)
+                {
+                    try
+                    {
+                        parsedValues[i] = _typeConverter.ConvertFrom(stringEntries[i].Trim());
+                        convertedCount++;
+                    }
+                    catch (FormatException)
+                    {
+                        // TODO log when upgraded to .Net6
+                        // https://github.com/dotnet/runtime/issues/42975
+                        // _logger.LogDebug(e, "Error converting value.");
+                    }
+                }
+
+                var typedValues = new T[convertedCount];
+                var typedValueIndex = 0;
+                for (var i = 0; i < stringEntries.Length; i++)
+                {
+                    if (parsedValues[i] != null)
+                    {
+                        typedValues.SetValue(parsedValues[i], typedValueIndex);
+                        typedValueIndex++;
+                    }
+                }
+
+                return typedValues;
+            }
+
+            return JsonSerializer.Deserialize<T[]>(ref reader, options);
+        }
+
+        /// <inheritdoc />
+        public override void Write(Utf8JsonWriter writer, T[]? value, JsonSerializerOptions options)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}
diff --git a/MediaBrowser.Common/Json/Converters/JsonNullableStructConverterFactory.cs b/MediaBrowser.Common/Json/Converters/JsonNullableStructConverterFactory.cs
index d5b54e3ca..e2a3d798a 100644
--- a/MediaBrowser.Common/Json/Converters/JsonNullableStructConverterFactory.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonNullableStructConverterFactory.cs
@@ -18,10 +18,10 @@ namespace MediaBrowser.Common.Json.Converters
         }
 
         /// <inheritdoc />
-        public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+        public override JsonConverter? CreateConverter(Type typeToConvert, JsonSerializerOptions options)
         {
             var structType = typeToConvert.GenericTypeArguments[0];
-            return (JsonConverter)Activator.CreateInstance(typeof(JsonNullableStructConverter<>).MakeGenericType(structType));
+            return (JsonConverter?)Activator.CreateInstance(typeof(JsonNullableStructConverter<>).MakeGenericType(structType));
         }
     }
-}
\ No newline at end of file
+}
diff --git a/MediaBrowser.Common/Json/Converters/JsonOmdbNotAvailableStringConverter.cs b/MediaBrowser.Common/Json/Converters/JsonOmdbNotAvailableStringConverter.cs
index 6a8790374..77cf46b70 100644
--- a/MediaBrowser.Common/Json/Converters/JsonOmdbNotAvailableStringConverter.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonOmdbNotAvailableStringConverter.cs
@@ -7,15 +7,21 @@ namespace MediaBrowser.Common.Json.Converters
     /// <summary>
     /// Converts a string <c>N/A</c> to <c>string.Empty</c>.
     /// </summary>
-    public class JsonOmdbNotAvailableStringConverter : JsonConverter<string>
+    public class JsonOmdbNotAvailableStringConverter : JsonConverter<string?>
     {
         /// <inheritdoc />
-        public override string Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        public override string? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
         {
+            if (reader.TokenType == JsonTokenType.Null)
+            {
+                return null;
+            }
+
             if (reader.TokenType == JsonTokenType.String)
             {
-                var str = reader.GetString();
-                if (str != null && str.Equals("N/A", StringComparison.OrdinalIgnoreCase))
+                // GetString can't return null here because we already handled it above
+                var str = reader.GetString()!;
+                if (str.Equals("N/A", StringComparison.OrdinalIgnoreCase))
                 {
                     return null;
                 }
@@ -23,11 +29,11 @@ namespace MediaBrowser.Common.Json.Converters
                 return str;
             }
 
-            return JsonSerializer.Deserialize<string>(ref reader, options);
+            return JsonSerializer.Deserialize<string?>(ref reader, options);
         }
 
         /// <inheritdoc />
-        public override void Write(Utf8JsonWriter writer, string value, JsonSerializerOptions options)
+        public override void Write(Utf8JsonWriter writer, string? value, JsonSerializerOptions options)
         {
             writer.WriteStringValue(value);
         }
diff --git a/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverter.cs b/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverter.cs
index c408a3be1..a8f6cfbec 100644
--- a/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverter.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverter.cs
@@ -9,67 +9,16 @@ namespace MediaBrowser.Common.Json.Converters
     /// Convert Pipe delimited string to array of type.
     /// </summary>
     /// <typeparam name="T">Type to convert to.</typeparam>
-    public class JsonPipeDelimitedArrayConverter<T> : JsonConverter<T[]>
+    public sealed class JsonPipeDelimitedArrayConverter<T> : JsonDelimitedArrayConverter<T>
     {
-        private readonly TypeConverter _typeConverter;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="JsonPipeDelimitedArrayConverter{T}"/> class.
         /// </summary>
-        public JsonPipeDelimitedArrayConverter()
+        public JsonPipeDelimitedArrayConverter() : base()
         {
-            _typeConverter = TypeDescriptor.GetConverter(typeof(T));
         }
 
         /// <inheritdoc />
-        public override T[] Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
-        {
-            if (reader.TokenType == JsonTokenType.String)
-            {
-                var stringEntries = reader.GetString()?.Split('|', StringSplitOptions.RemoveEmptyEntries);
-                if (stringEntries == null || stringEntries.Length == 0)
-                {
-                    return Array.Empty<T>();
-                }
-
-                var parsedValues = new object[stringEntries.Length];
-                var convertedCount = 0;
-                for (var i = 0; i < stringEntries.Length; i++)
-                {
-                    try
-                    {
-                        parsedValues[i] = _typeConverter.ConvertFrom(stringEntries[i].Trim());
-                        convertedCount++;
-                    }
-                    catch (FormatException)
-                    {
-                        // TODO log when upgraded to .Net6
-                        // https://github.com/dotnet/runtime/issues/42975
-                        // _logger.LogDebug(e, "Error converting value.");
-                    }
-                }
-
-                var typedValues = new T[convertedCount];
-                var typedValueIndex = 0;
-                for (var i = 0; i < stringEntries.Length; i++)
-                {
-                    if (parsedValues[i] != null)
-                    {
-                        typedValues.SetValue(parsedValues[i], typedValueIndex);
-                        typedValueIndex++;
-                    }
-                }
-
-                return typedValues;
-            }
-
-            return JsonSerializer.Deserialize<T[]>(ref reader, options);
-        }
-
-        /// <inheritdoc />
-        public override void Write(Utf8JsonWriter writer, T[] value, JsonSerializerOptions options)
-        {
-            throw new NotImplementedException();
-        }
+        protected override char Delimiter => '|';
     }
 }
diff --git a/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverterFactory.cs b/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverterFactory.cs
index 5e77223ef..1bebc49ec 100644
--- a/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverterFactory.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonPipeDelimitedArrayConverterFactory.cs
@@ -19,10 +19,10 @@ namespace MediaBrowser.Common.Json.Converters
         }
 
         /// <inheritdoc />
-        public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+        public override JsonConverter? CreateConverter(Type typeToConvert, JsonSerializerOptions options)
         {
             var structType = typeToConvert.GetElementType() ?? typeToConvert.GenericTypeArguments[0];
-            return (JsonConverter)Activator.CreateInstance(typeof(JsonPipeDelimitedArrayConverter<>).MakeGenericType(structType));
+            return (JsonConverter?)Activator.CreateInstance(typeof(JsonPipeDelimitedArrayConverter<>).MakeGenericType(structType));
         }
     }
 }
diff --git a/MediaBrowser.Common/Json/Converters/JsonStringConverter.cs b/MediaBrowser.Common/Json/Converters/JsonStringConverter.cs
index 669b3cd07..6cd980e48 100644
--- a/MediaBrowser.Common/Json/Converters/JsonStringConverter.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonStringConverter.cs
@@ -9,10 +9,10 @@ namespace MediaBrowser.Common.Json.Converters
     /// <summary>
     /// Converter to allow the serializer to read strings.
     /// </summary>
-    public class JsonStringConverter : JsonConverter<string>
+    public class JsonStringConverter : JsonConverter<string?>
     {
         /// <inheritdoc />
-        public override string Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        public override string? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
         {
             return reader.TokenType switch
             {
@@ -23,7 +23,7 @@ namespace MediaBrowser.Common.Json.Converters
         }
 
         /// <inheritdoc />
-        public override void Write(Utf8JsonWriter writer, string value, JsonSerializerOptions options)
+        public override void Write(Utf8JsonWriter writer, string? value, JsonSerializerOptions options)
         {
             writer.WriteStringValue(value);
         }
@@ -36,4 +36,4 @@ namespace MediaBrowser.Common.Json.Converters
             return Encoding.UTF8.GetString(utf8Bytes);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/MediaBrowser.Common/Json/Converters/JsonVersionConverter.cs b/MediaBrowser.Common/Json/Converters/JsonVersionConverter.cs
index f69e868cc..81c093c54 100644
--- a/MediaBrowser.Common/Json/Converters/JsonVersionConverter.cs
+++ b/MediaBrowser.Common/Json/Converters/JsonVersionConverter.cs
@@ -14,7 +14,7 @@ namespace MediaBrowser.Common.Json.Converters
     {
         /// <inheritdoc />
         public override Version Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
-            => new Version(reader.GetString());
+            => new Version(reader.GetString()!); // Will throw ArgumentNullException on null
 
         /// <inheritdoc />
         public override void Write(Utf8JsonWriter writer, Version value, JsonSerializerOptions options)
diff --git a/MediaBrowser.Common/MediaBrowser.Common.csproj b/MediaBrowser.Common/MediaBrowser.Common.csproj
index 0d9f78704..0299a8456 100644
--- a/MediaBrowser.Common/MediaBrowser.Common.csproj
+++ b/MediaBrowser.Common/MediaBrowser.Common.csproj
@@ -33,6 +33,7 @@
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <Nullable>enable</Nullable>
     <AnalysisMode>AllEnabledByDefault</AnalysisMode>
     <CodeAnalysisRuleSet>../jellyfin.ruleset</CodeAnalysisRuleSet>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
diff --git a/MediaBrowser.Common/Net/INetworkManager.cs b/MediaBrowser.Common/Net/INetworkManager.cs
index 185df5b77..b93939730 100644
--- a/MediaBrowser.Common/Net/INetworkManager.cs
+++ b/MediaBrowser.Common/Net/INetworkManager.cs
@@ -1,4 +1,3 @@
-#nullable enable
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
diff --git a/MediaBrowser.Common/Net/IPHost.cs b/MediaBrowser.Common/Net/IPHost.cs
index 7156ce618..5db8817ee 100644
--- a/MediaBrowser.Common/Net/IPHost.cs
+++ b/MediaBrowser.Common/Net/IPHost.cs
@@ -1,4 +1,3 @@
-#nullable enable
 using System;
 using System.Diagnostics;
 using System.Linq;
diff --git a/MediaBrowser.Common/Net/IPNetAddress.cs b/MediaBrowser.Common/Net/IPNetAddress.cs
index 589aad4b0..f6e3971bf 100644
--- a/MediaBrowser.Common/Net/IPNetAddress.cs
+++ b/MediaBrowser.Common/Net/IPNetAddress.cs
@@ -1,4 +1,3 @@
-#nullable enable
 using System;
 using System.Net;
 using System.Net.Sockets;
diff --git a/MediaBrowser.Common/Net/IPObject.cs b/MediaBrowser.Common/Net/IPObject.cs
index 3542dcd75..2612268fd 100644
--- a/MediaBrowser.Common/Net/IPObject.cs
+++ b/MediaBrowser.Common/Net/IPObject.cs
@@ -1,4 +1,3 @@
-#nullable enable
 using System;
 using System.Net;
 using System.Net.Sockets;
diff --git a/MediaBrowser.Common/Plugins/BasePlugin.cs b/MediaBrowser.Common/Plugins/BasePlugin.cs
index ad5a7338d..8972089a8 100644
--- a/MediaBrowser.Common/Plugins/BasePlugin.cs
+++ b/MediaBrowser.Common/Plugins/BasePlugin.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.IO;
 using System.Reflection;
diff --git a/MediaBrowser.Common/Plugins/BasePluginOfT.cs b/MediaBrowser.Common/Plugins/BasePluginOfT.cs
index e074cc6a0..8a6d28e0f 100644
--- a/MediaBrowser.Common/Plugins/BasePluginOfT.cs
+++ b/MediaBrowser.Common/Plugins/BasePluginOfT.cs
@@ -1,4 +1,6 @@
+#nullable disable
 #pragma warning disable SA1649 // File name should match first type name
+
 using System;
 using System.IO;
 using System.Runtime.InteropServices;
diff --git a/MediaBrowser.Common/Plugins/IPlugin.cs b/MediaBrowser.Common/Plugins/IPlugin.cs
index b2ba1179c..01e0a536d 100644
--- a/MediaBrowser.Common/Plugins/IPlugin.cs
+++ b/MediaBrowser.Common/Plugins/IPlugin.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using MediaBrowser.Model.Plugins;
 
diff --git a/MediaBrowser.Common/Plugins/IPluginManager.cs b/MediaBrowser.Common/Plugins/IPluginManager.cs
index 0e2e814cb..176bcbbd5 100644
--- a/MediaBrowser.Common/Plugins/IPluginManager.cs
+++ b/MediaBrowser.Common/Plugins/IPluginManager.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Collections.Generic;
 using System.Reflection;
diff --git a/MediaBrowser.Common/Plugins/LocalPlugin.cs b/MediaBrowser.Common/Plugins/LocalPlugin.cs
index 12a1ad1ec..4c8e2d504 100644
--- a/MediaBrowser.Common/Plugins/LocalPlugin.cs
+++ b/MediaBrowser.Common/Plugins/LocalPlugin.cs
@@ -1,4 +1,3 @@
-#nullable enable
 using System;
 using System.Collections.Generic;
 using MediaBrowser.Model.Plugins;
diff --git a/MediaBrowser.Common/Plugins/PluginManifest.cs b/MediaBrowser.Common/Plugins/PluginManifest.cs
index 4c724f694..2910dbe14 100644
--- a/MediaBrowser.Common/Plugins/PluginManifest.cs
+++ b/MediaBrowser.Common/Plugins/PluginManifest.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Text.Json.Serialization;
 using MediaBrowser.Model.Plugins;
diff --git a/MediaBrowser.Common/Progress/ActionableProgress.cs b/MediaBrowser.Common/Progress/ActionableProgress.cs
index fe7cb1078..0ba46ea3b 100644
--- a/MediaBrowser.Common/Progress/ActionableProgress.cs
+++ b/MediaBrowser.Common/Progress/ActionableProgress.cs
@@ -14,9 +14,9 @@ namespace MediaBrowser.Common.Progress
         /// <summary>
         /// The _actions.
         /// </summary>
-        private Action<T> _action;
+        private Action<T>? _action;
 
-        public event EventHandler<T> ProgressChanged;
+        public event EventHandler<T>? ProgressChanged;
 
         /// <summary>
         /// Registers the action.
diff --git a/MediaBrowser.Common/Progress/SimpleProgress.cs b/MediaBrowser.Common/Progress/SimpleProgress.cs
index 988d8ad34..7071f2bc3 100644
--- a/MediaBrowser.Common/Progress/SimpleProgress.cs
+++ b/MediaBrowser.Common/Progress/SimpleProgress.cs
@@ -7,7 +7,7 @@ namespace MediaBrowser.Common.Progress
 {
     public class SimpleProgress<T> : IProgress<T>
     {
-        public event EventHandler<T> ProgressChanged;
+        public event EventHandler<T>? ProgressChanged;
 
         public void Report(T value)
         {
diff --git a/MediaBrowser.Common/Providers/ProviderIdParsers.cs b/MediaBrowser.Common/Providers/ProviderIdParsers.cs
index 64c2e1976..33d09ed38 100644
--- a/MediaBrowser.Common/Providers/ProviderIdParsers.cs
+++ b/MediaBrowser.Common/Providers/ProviderIdParsers.cs
@@ -1,6 +1,4 @@
-#nullable enable
-
-using System;
+using System;
 using System.Diagnostics.CodeAnalysis;
 
 namespace MediaBrowser.Common.Providers
diff --git a/MediaBrowser.Common/Updates/IInstallationManager.cs b/MediaBrowser.Common/Updates/IInstallationManager.cs
index 0844c2d79..c2a28e0a2 100644
--- a/MediaBrowser.Common/Updates/IInstallationManager.cs
+++ b/MediaBrowser.Common/Updates/IInstallationManager.cs
@@ -1,5 +1,3 @@
-#nullable enable
-
 using System;
 using System.Collections.Generic;
 using System.Threading;
diff --git a/MediaBrowser.Common/Updates/InstallationEventArgs.cs b/MediaBrowser.Common/Updates/InstallationEventArgs.cs
index adf336313..f4f759955 100644
--- a/MediaBrowser.Common/Updates/InstallationEventArgs.cs
+++ b/MediaBrowser.Common/Updates/InstallationEventArgs.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using MediaBrowser.Model.Updates;
 
diff --git a/MediaBrowser.Common/Updates/InstallationFailedEventArgs.cs b/MediaBrowser.Common/Updates/InstallationFailedEventArgs.cs
index 46f10c84f..d37146195 100644
--- a/MediaBrowser.Common/Updates/InstallationFailedEventArgs.cs
+++ b/MediaBrowser.Common/Updates/InstallationFailedEventArgs.cs
@@ -1,3 +1,4 @@
+#nullable disable
 #pragma warning disable CS1591
 
 using System;