When our contentpane controls include a XamDataGrid, the WPF designer crashes after a few seconds with the following error, our project is a .Net 4.0 project still, but we're using VS2012, this seems to only occur when a XamDataGrid is present, and ideas on how to resolve this please?

Cheers

Jonathan

Microsoft.Expression.DesignHost.Isolation.Remoting.RemoteException
Object reference not set to an instance of an object.
at Microsoft.Expression.DesignModel.Metadata.MetadataStore.GetTypeConverter(Type type)
at Microsoft.Expression.WpfPlatform.WpfDesignTimeProperties.RegisterProperty(IPropertyId neutralPropertyKey, IType declaringType, FrameworkPropertyMetadataOptions options, PropertyChangedCallback callback)
at Microsoft.Expression.WpfPlatform.WpfCommonDesignTimeProperties.Initialize(WpfDesignTimeProperties designTimeProperties)
at Microsoft.Expression.WpfPlatform.WpfDesignTimeProperties..ctor(PlatformMetadataBase platformMetadata)
at Microsoft.Expression.WpfPlatform.WpfPlatformMetadata.OnInitialize()
at Microsoft.Expression.WpfPlatform.WpfPlatform.Initialize()
at Microsoft.Expression.Platform.PlatformCreatorBase.CreatePlatform(IPlatformReferenceAssemblyResolver referenceAssemblyResolver)
at Microsoft.Expression.DesignSurface.Project.ProjectContextBase.Initialize()
at Microsoft.Expression.DesignSurface.Project.XamlProjectContext.Initialize()
at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.GetProjectContext(IHostProject project, IPlatform platform, Boolean create)
at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.<GetReferencedProjects>d__d.MoveNext()
at Microsoft.Expression.DesignSurface.Project.ProjectContextBase.XamlProjectMetadata.GetAssemblyForTypeResolve(String assemblyName)
at Microsoft.Expression.DesignModel.Metadata.TypeResolver.GetType(ClrNamespaceIdentifier clrNamespaceIdentifier, String typeName)
at Microsoft.Expression.DesignModel.Metadata.TypeResolver.ResolveType(ITypeId typeId)
at Microsoft.Expression.DesignModel.Metadata.ProjectNeutralTypesAttributeTable.ResolveType(ITypeResolver typeResolver, ITypeId typeId)
at Microsoft.Expression.DesignModel.Metadata.ProjectNeutralTypesAttributeTable.RegisterDataGridAttributeTable(ITypeResolver typeResolver)
at Microsoft.Expression.WpfPlatform.WpfPlatform.RefreshProjectSpecificMetadata(ITypeResolver typeResolver, ITypeMetadataFactory typeMetadataFactory)
at Microsoft.Expression.DesignSurface.Project.ProjectContextBase.Initialize()
at Microsoft.Expression.DesignSurface.Project.XamlProjectContext.Initialize()
at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.GetProjectContext(IHostProject project, IPlatform platform, Boolean create)
at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.<GetReferencedProjects>d__d.MoveNext()
at Microsoft.Expression.DesignSurface.Project.ProjectContextBase.XamlProjectMetadata.GetAssemblyForTypeResolve(String assemblyName)
at Microsoft.Expression.DesignModel.Metadata.TypeResolver.GetType(ClrNamespaceIdentifier clrNamespaceIdentifier, String typeName)
at Microsoft.Expression.DesignModel.Metadata.TypeResolver.ResolveType(ITypeId typeId)
at Microsoft.Expression.DesignModel.Metadata.ProjectNeutralTypesAttributeTable.ResolveType(ITypeResolver typeResolver, ITypeId typeId)
at Microsoft.Expression.DesignModel.Metadata.ProjectNeutralTypesAttributeTable.RegisterDataGridAttributeTable(ITypeResolver typeResolver)
at Microsoft.Expression.WpfPlatform.WpfPlatform.RefreshProjectSpecificMetadata(ITypeResolver typeResolver, ITypeMetadataFactory typeMetadataFactory)
at Microsoft.Expression.DesignSurface.Project.ProjectContextBase.Initialize()
at Microsoft.Expression.DesignSurface.Project.XamlProjectContext.Initialize()
at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.GetProjectContext(IHostProject project, IPlatform platform, Boolean create)
at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.<GetContextsInActiveSolution>d__1e.MoveNext()
at Microsoft.Expression.DesignSurface.SceneCommands.ReplaceStyleTemplateCommand.ResolveDefaultStyle(SceneNode targetElement, Object defaultStyleKey, Boolean allowDefaultStyle, DocumentNode& currentStyle, Boolean& isThemeStyle, IList`1& auxillaryResources)
at Microsoft.Expression.DesignSurface.SceneCommands.ReplaceStyleTemplateCommand.ProvideCurrentStyle(SceneNode targetElement, IType targetType, PropertyReference targetPropertyReference, Boolean allowDefaultStyle, IList`1& auxillaryResources)
at Microsoft.Expression.DesignSurface.SceneCommands.EditCopyOfStyleCommand.get_IsEnabled()
at Microsoft.Expression.Utility.Commands.Command.GetProperty(String propertyName)
at Microsoft.Expression.DesignSurface.SceneCommands.ReplaceStyleTemplateCommand.GetProperty(String propertyName)
at Microsoft.Expression.DesignSurface.View.SceneView.UpdateCommandState(IEnumerable`1 commandNames, Boolean forceRefresh)
at Microsoft.Expression.DesignSurface.View.SceneView.SelectionManager_LateActiveSceneUpdatePhase(Object sender, SceneUpdatePhaseEventArgs args)
at Microsoft.Expression.DesignSurface.ViewModel.SceneUpdatePhaseEventHandler.Invoke(Object sender, SceneUpdatePhaseEventArgs args)
at Microsoft.Expression.DesignSurface.Selection.SelectionManager.FireLateActiveSceneUpdatePhase(SceneUpdatePhaseEventArgs args)
at Microsoft.Expression.DesignSurface.Pipeline.SceneViewUpdateScheduleTask.UpdateLate()
at Microsoft.Expression.Utility.Scheduler.ScheduleTask.Update()
at Microsoft.Expression.Utility.Scheduler.SchedulingService.DispatchTasksAtPriority(DispatcherPriority priority)
at Microsoft.Expression.Utility.Scheduler.SchedulingService.DispatcherToken.Dispatch(Object arg)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.DispatcherOperation.InvokeImpl()
at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Windows.Threading.DispatcherOperation.Invoke()
at System.Windows.Threading.Dispatcher.ProcessQueue()
at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.Run()
at System.Windows.Application.RunDispatcher(Object ignore)
at System.Windows.Application.RunInternal(Window window)
at System.Windows.Application.Run(Window window)
at System.Windows.Application.Run()
at Microsoft.Expression.DesignHost.Isolation.IsolationProcess.RunApplication()
at Microsoft.Expression.DesignHost.Isolation.IsolationProcess.<>c__DisplayClass2.<Main>b__0()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()