or
System.NullReferenceException: Object reference not set to an instance of an object.
at Telerik.WinControls.UI.GridViewEditManager.InitializeEditor(IInputEditor activeEditor)
at Telerik.WinControls.UI.GridViewEditManager.BeginEdit()
at Telerik.WinControls.UI.GridRowBehavior.OnMouseUpLeft(MouseEventArgs e)
at Telerik.WinControls.UI.GridRowBehavior.OnMouseUp(MouseEventArgs e)
at Telerik.WinControls.UI.BaseGridBehavior.OnMouseUp(MouseEventArgs e)
at Telerik.WinControls.UI.RadGridView.OnMouseUp(MouseEventArgs e)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at Telerik.WinControls.RadControl.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)