CollectionType can be null

Emby.Server.Implementations/Library/LibraryManager.cs

@@ -1240,7 +1240,7 @@ namespace Emby.Server.Implementations.Library
             return info;
         }
 
-        private CollectionTypeOptions GetCollectionType(string path)
+        private CollectionTypeOptions? GetCollectionType(string path)
         {
             var files = _fileSystem.GetFilePaths(path, new[] { ".collection" }, true, false);
             foreach (var file in files)
@@ -1253,7 +1253,7 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            throw new FileNotFoundException("Coudn't find an appropriate collection type file.");
+            return null;
         }
 
         /// <summary>

MediaBrowser.Model/Entities/VirtualFolderInfo.cs

@@ -35,7 +35,7 @@ namespace MediaBrowser.Model.Entities
         /// Gets or sets the type of the collection.
         /// </summary>
         /// <value>The type of the collection.</value>
-        public CollectionTypeOptions CollectionType { get; set; }
+        public CollectionTypeOptions? CollectionType { get; set; }
 
         public LibraryOptions LibraryOptions { get; set; }