If AJAX is enabled for the RadGrid and re-ordering its columns, a JavaScript exception is thrown: "uncaught typeerror: cannot set property 'control' of undefined"
Thank you for taking your time reporting this issue!
We've done some research on this problem, and we found that the problem appears if using RadAjaxManager or RadAjaxPanel to enable AJAX for the Grid and there is a column hidden using the Visible property.
For this case, we suggest one of the following workarounds: