I have a problem with the resources not being found for the telerik controls. I have narrowed down the problem to .net 4.5 or installing kb 2836939 for .net 4.0. If I have a .net 4.0 installation on a windows 2008 r2 server without kb 2836939 it works fine. As soon as I install it, I get the 404 errors. If I uninstall it, it goes back to working. We are using Telerik.web.ui version 2013.2.717.35. I do not need .net 4.5 at this time so fixing the .net 4.0 error would be just as useful. I need kb 2836939 to fix postback errors in IE11. If purchasing a newer version of your controls will guarantee to fix the problem even if means installing asp.net 4.5, please let me know.