I'm afraid your toolbox cache may have been corrupted. You can make a full reset of the toolbox by deleting the cache to make sure it is working properly. Note that this will revert the toolbox to its default state
. To reset the toolbox follow these steps:
- Close all Visual Studio 2010 instances.
- Open Windows Explorer and navigate to the location: %localappdata%\Microsoft\VisualStudio\10.0
- Delete all .tbd files (note that some of them are hidden);
- Open a web project in Visual Studio and check whether the toolbox shows the controls properly.
Hope we get the issue resolved soon.
the Telerik team