I will email you directly to your address on file. Please respond to it with a screen shot of your VS about screen. It may take two or more to show all of the "Installed products."
I searched the error on Google without much luck. This is a very new error to us and we are not certain what causes it nor how to fix it. Hopefully your screen shots compared with the other customer's and our own VS configuration will shed some light on this.
In the meantime he provided a work-around to get the Test Studio plugin working:
1. Create a VS test project.
3. Close the project (I closed VS)
5. Add Telerik test case
the Telerik team
for a live 'What's New in Test Studio R1 2011 SP2' event on Tuesday, July 19 at 2pm EST!
Have you looked at the new Online User Guide
for Telerik Test Studio?