Merge pull request #1898 from Bond-009/jsonfix

Fix Json serialization error

(cherry picked from commit 91600b1c81)
Signed-off-by: Joshua Boniface <joshua@boniface.me>

MediaBrowser.Controller/Entities/AggregateFolder.cs

@@ -2,13 +2,13 @@ using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text.Json.Serialization;
 using System.Threading;
 using System.Threading.Tasks;
 using MediaBrowser.Controller.IO;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Providers;
 using MediaBrowser.Model.IO;
-using MediaBrowser.Model.Serialization;
 
 namespace MediaBrowser.Controller.Entities
 {
@@ -23,7 +23,7 @@ namespace MediaBrowser.Controller.Entities
             PhysicalLocationsList = Array.Empty<string>();
         }
 
-        [IgnoreDataMember]
+        [JsonIgnore]
         public override bool IsPhysicalRoot => true;
 
         public override bool CanDelete()
@@ -31,7 +31,7 @@ namespace MediaBrowser.Controller.Entities
             return false;
         }
 
-        [IgnoreDataMember]
+        [JsonIgnore]
         public override bool SupportsPlayedStatus => false;
 
         /// <summary>
@@ -45,7 +45,7 @@ namespace MediaBrowser.Controller.Entities
         /// <value>The virtual children.</value>
         public ConcurrentBag<BaseItem> VirtualChildren => _virtualChildren;
 
-        [IgnoreDataMember]
+        [JsonIgnore]
         public override string[] PhysicalLocations => PhysicalLocationsList;
 
         public string[] PhysicalLocationsList { get; set; }