2 files changed, 15 insertions, 1 deletions
diff --git a/MediaBrowser.Server.Implementations/Session/SessionManager.cs b/MediaBrowser.Server.Implementations/Session/SessionManager.cs
index 77843ef6b2..4386b785ad 100644
--- a/MediaBrowser.Server.Implementations/Session/SessionManager.cs
+++ b/MediaBrowser.Server.Implementations/Session/SessionManager.cs
@@ -404,6 +404,10 @@ namespace MediaBrowser.Server.Implementations.Session
         /// <returns>SessionInfo.</returns>
         private async Task<SessionInfo> GetSessionInfo(string appName, string appVersion, string deviceId, string deviceName, string remoteEndPoint, User user)
         {
+            if (string.IsNullOrWhiteSpace(deviceId))
+            {
+                throw new ArgumentNullException("deviceId");
+            }
             var key = GetSessionKey(appName, deviceId);
 
             await _sessionLock.WaitAsync(CancellationToken.None).ConfigureAwait(false);
@@ -1748,6 +1752,11 @@ namespace MediaBrowser.Server.Implementations.Session
 
         public void ReportNowViewingItem(string sessionId, string itemId)
         {
+            if (string.IsNullOrWhiteSpace(itemId))
+            {
+                throw new ArgumentNullException("itemId");
+            }
+
             var item = _libraryManager.GetItemById(new Guid(itemId));
 
             var info = GetItemInfo(item, null, null);
diff --git a/MediaBrowser.Server.Implementations/Session/SessionWebSocketListener.cs b/MediaBrowser.Server.Implementations/Session/SessionWebSocketListener.cs
index 602bc4876b..ddd7ba53a6 100644
--- a/MediaBrowser.Server.Implementations/Session/SessionWebSocketListener.cs
+++ b/MediaBrowser.Server.Implementations/Session/SessionWebSocketListener.cs
@@ -230,7 +230,12 @@ namespace MediaBrowser.Server.Implementations.Session
             {
                 var vals = message.Data.Split('|');
 
-                _sessionManager.ReportNowViewingItem(session.Id, vals[1]);
+                var itemId = vals[1];
+
+                if (!string.IsNullOrWhiteSpace(itemId))
+                {
+                    _sessionManager.ReportNowViewingItem(session.Id, itemId);
+                }
             }
         }