GridView generates and System.NullReferenceException

[Pieter]

I have GridView 2012.3.1314.40. This view is created with EnableColumnVirtualization and EnableRowVirtualization true.
Data is added slowly by another thread.

When browsing this GridView I get an System.NullReferenceException with the following stack

Error in function Unhandled exception: System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Windows.Controls.GridView.GridViewHeaderCell.SetLeftGripperVisibility()
   at Telerik.Windows.Controls.GridView.GridViewHeaderCell.HookupGripperEvents()
   at Telerik.Windows.Controls.GridView.GridViewHeaderCell.OnApplyTemplate()
   at System.Windows.FrameworkElement.ApplyTemplate()
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.MeasureCell(GridViewColumn column, GridViewCellBase cell, Size size)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.RealizeAndMeasureCells(Int32 startIndex, Int32 predictedLastIndex, Func`2 calculateNextIndex)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.UpdateVirtualizedCells()
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.MeasureOverride(Size availableSize)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.ContextLayoutManager.UpdateLayout()
   at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
   at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork()
   at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
   at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
   at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
   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 Telerik.Windows.Controls.GridView.GridViewHeaderCell.SetLeftGripperVisibility()
   at Telerik.Windows.Controls.GridView.GridViewHeaderCell.HookupGripperEvents()
   at Telerik.Windows.Controls.GridView.GridViewHeaderCell.OnApplyTemplate()
   at System.Windows.FrameworkElement.ApplyTemplate()
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.MeasureCell(GridViewColumn column, GridViewCellBase cell, Size size)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.RealizeAndMeasureCells(Int32 startIndex, Int32 predictedLastIndex, Func`2 calculateNextIndex)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.UpdateVirtualizedCells()
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.MeasureOverride(Size availableSize)
   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
   at System.Windows.UIElement.Measure(Size availableSize)
   at System.Windows.ContextLayoutManager.UpdateLayout()
   at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
   at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork()
   at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
   at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
   at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
   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)

I do not know what is causing this exception and how to prevent or catch it without killing my application first.

Any help would be appreciated.

Pieter

[Dimitrina]

Hello Pieter,

We have fixed a similar exception for the Q1 2013 release. Would you please download it and test if you can reproduce the issue with it?

Regards,
Didie
the Telerik team

[Pieter]

Didie,

Thanks for your answer!
We did update the Telerik dll's, and indeed the problem did not occur again ever since.

Pieter