fix crash with null properties from online objects

Author: LeftofZen

AvaGui/Models/ObjectEditorModel.cs

@@ -209,8 +209,8 @@ public bool TryLoadObject(FileSystemItem filesystemItem, out UiLocoFile? uiLocoF
 						}
 
 						Logger.Info($"Downloaded object {filesystemItem.Name} with unique id {uniqueObjectId} and added it to the local cache");
-						Logger.Debug($"{filesystemItem.Name} has authors=[{string.Join(", ", locoObj.Authors.Select(x => x.Name))}], tags=[{string.Join(", ", locoObj.Tags.Select(x => x.Name))}], modpacks=[{string.Join(", ", locoObj.Modpacks.Select(x => x.Name))}], licence={locoObj.Licence}");
-						OnlineCache.Add(uniqueObjectId, locoObj);
+						Logger.Debug($"{filesystemItem.Name} has authors=[{string.Join(", ", locoObj?.Authors?.Select(x => x.Name) ?? [])}], tags=[{string.Join(", ", locoObj?.Tags?.Select(x => x.Name) ?? [])}], modpacks=[{string.Join(", ", locoObj?.Modpacks?.Select(x => x.Name) ?? [])}], licence={locoObj?.Licence}");
+						OnlineCache.Add(uniqueObjectId, locoObj!);
 					}
 					else
 					{