I am sorry to hear that you are experiencing problems with the RadControls for ASP.NET AJAX.
My first suggestion is to use the Upgrade wizard to upgrade your project from the trial version to the licensed one. You can launch the wizard from the Telerik menu in Visual Studio. After the upgrade I recommend you to rebuild your project.
If you still experience design-time problems then you can review our troubleshooting article - http://www.telerik.com/help/aspnet-ajax/introduction-design-time-troubleshooting.html
I hope this helps you.
the Telerik team
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