Hi Doga Ercan,
I'm sorry you are experiencing this problem. This a known issue
with our previous official release 2011.2.1117. It's already fixed in our current SP2 release. You can download it from your Telerik account here: Public URL
. Note that the Execution server and your main machine must have the same version of Test Studio, so you need to upgrade them both.
Please, let me know if the issue persist after upgrading to the new release.
the Telerik team