Hello,

From time to time i have this error and i'm unable to understand what is causing it and how to reproduce. Does anybody have any ideea about what is causing it and how to fix?

System.ArgumentNullException: Value cannot be null.
Parameter name: id
at EPiServer.Framework.Validator.ThrowIfNull(String name, Object value)
at EPiServer.Cms.Shell.UI.Rest.Internal.InUseNotificationStore.Get(ContentReference id)
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.b__3d()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.b__1c()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.b__1e(IAsyncResult asyncResult)
at EPiServer.Shell.Services.Rest.RestControllerBase.EndExecute(IAsyncResult asyncResult)
at EPiServer.Shell.Services.Rest.RestHttpHandler.EndProcessRequest(IAsyncResult result)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)