StackOverFlow exception when the user sorts a GridView control. The exception occurs in the CellValueNeeded method when accessing e.RowIndex. The GridView is in VirtualMode. The error doesn't occur during the initial load of the data.
The issue is duplicated with feedback item FIX. RadGridView - invalid processing of CellValueNeeded event when sorting/filtering is applied in virtual mode. You can track its progress, subscribe for status changes and add your vote/comment to it on the following link: http://feedback.telerik.com/Project/154/Feedback/Details/112031-fix-radgridview-invalid-processing-of-cellvalueneeded-event-when-sorting-filte