It seems that when loading, the saved column info cannot resolve its actual column in the GridView. It could be that the columns of the GridView have not already loaded or the column does not exist in the GridView. You can troubleshoot this with the custom provider class and check whether all of the GridView columns are loaded when the sort descriptors are being restored.
the Telerik team
Explore the entire Telerik portfolio by downloading the Ultimate Collection trial package. Get it now >>