My company just purchased the Developer license for the ASP.NET version 2011.1.519.35 control set. After complete removal of the trial version and re-installation of the purchased product I am now receiving the error in the attached controlerror.png file. I removed all instances of Telerik from the web.config during the removal of the Trial version. I then copied the new telerik.web.ui.dll and placed it into the solution libary folder and references that dll in the solution. I then ran the 'configure project' selection from Telerik menu to bring my web.config into compliance for this version. No existing controls in the project will render either all controls are showing different errors ( see attached Page1Errors.png) any help would be appreciated.