Hello!

Quite often our editors get stuck at a blank page and page tree when in editing mode. We haven't managed to reproduce it in our test environment but finally received a stack trace from production. Status 500 is returned for multiple requests to /EPiserver/cms/Stores/contentstructure and /EPiserver/cms/Stores/contentdata. The stack trace however points to Notifications and InUseNotificationRepository, but we can't find a solution.

It seems as if it is related to this bug http://world.episerver.com/documentation/Release-Notes/ReleaseNote/?releaseNoteId=114969. However, we are using EPi 10.3.1 and the bug above was found in EPi 7. We couldn't find the "linked SupportCase" mentioned in the bug.

This is the stacktrace:

Server Error in '/' Application.


            
 Object reference not set to an instance of an object. 

            

             Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

            



             Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.



            Source Error: 



            

               

                  

                      

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

                  
               
            

            


            Stack Trace: 



            

               

                  

                      

[NullReferenceException: Object reference not set to an instance of an object.]
   EPiServer.Shell.Notification.<>c__DisplayClass10_0.b__0(InUseNotification notification) +15
   System.Linq.WhereSelectListIterator`2.MoveNext() +122
   System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +451
   System.Linq.Enumerable.ToList(IEnumerable`1 source) +69
   EPiServer.Cms.Shell.UI.Rest.Models.Transforms.Internal.ContentDataModelBaseTransform.TransformInstance(IContent source, ContentDataStoreModelBase target, IModelTransformContext context) +174
   EPiServer.Cms.Shell.UI.Rest.Models.Transforms.d__4.MoveNext() +305
   EPiServer.Cms.Shell.UI.Rest.Models.Transforms.d__4.MoveNext() +136
   EPiServer.Cms.Shell.UI.Rest.Models.Transforms.d__4.MoveNext() +136
   System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +117
   System.Linq.Enumerable.First(IEnumerable`1 source) +146
   EPiServer.Cms.Shell.UI.Rest.Internal.ContentStore.GetContent(ContentReference contentReference, DefaultQueryParameters queryParameters) +271
   EPiServer.Cms.Shell.UI.Rest.Internal.ContentStore.Get(ContentReference id, String query, ContentReference referenceId, ContentReference[] references, String[] typeIdentifiers, Nullable`1 allLanguages, IEnumerable`1 sortColumns, ItemRange range) +388
   lambda_method(Closure , ControllerBase , Object[] ) +479
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +228
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +34
   System.Web.Mvc.Async.AsyncControllerActionInvoker.b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) +38
   System.Web.Mvc.Async.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) +70
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +41
   System.Web.Mvc.Async.AsyncInvocationWithFilters.b__3d() +71
   System.Web.Mvc.Async.<>c__DisplayClass46.b__3f() +386
   System.Web.Mvc.Async.<>c__DisplayClass46.b__3f() +386
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +42
   System.Web.Mvc.Async.<>c__DisplayClass2b.b__1c() +38
   System.Web.Mvc.Async.<>c__DisplayClass21.b__1e(IAsyncResult asyncResult) +186
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +38
   EPiServer.Shell.Services.Rest.RestControllerBase.EndExecute(IAsyncResult asyncResult) +60
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +399
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +157


                  
               
            

            


            


            Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.6.1590.0

            

    

/Martin