Should be returned as a list - otherwise we'll get a new collection and new tab objects each time we iterate over it

src/Umbraco.Web/Editors/DashboardController.cs

@@ -215,7 +215,7 @@ namespace Umbraco.Web.Editors
                     Alias = y.Alias,
                     View = y.View
                 })
-            });
+            }).ToList();
         }
     }
 }