Can this issue be related to this known problem
? If so, note it has been verified and fixed shortly after our Q1 2015 release, and we apologize for the inconvenience it caused you. The fix is included in the latest internal build of the product, which is available for download from your Telerik account's > DevCraft Ultimate > UI for ASP.NET MVC
product downloads section.
Please migrate to the new version and let us know whether this helps.