I have a column in a RadGridView with its CellEditTemplate set to a control containing a RadComboBox.

I get the error:

System.Exception: Catastrophic failure (Exception from HRESULT: 0x8000FFFF (E_UNEXPECTED))
   at MS.Internal.XcpImports.CheckHResult(UInt32 hr)
   at MS.Internal.XcpImports.Control_Raise(Control control, IManagedPeerBase arguments, Byte nDelegate)
   at System.Windows.Controls.TextBox.OnKeyDown(KeyEventArgs e)
   at System.Windows.Controls.Control.OnKeyDown(Control ctrl, EventArgs e)
   at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)

When the user presses the down arrow to open the drop down after the cell has entered edit mode.

I wondered if it was a grid related issue but other controls work fine in this scenario. If the user uses the mouse to open the drop down it works fine, it's only when using the keyboard. Same control works fine when not being uses as a template in a grid.

Any ideas? My version is 2011.1.419.1040

Hi Paul,

 
Thank you for contacting us.

We tried to reproduce the problem, but to no avail, You could a sample project and a video attached. Could you please point me to the right direction so I can reproduce the issue? I am glad to assist you further.

Kind regards,
George
the Telerik team