I'm sorry to hear you're having trouble with automating this control.
The actual failure message is missing from the Log you've provided. I'm not sure why that is but without the failure message we have almost no information relating to the nature of the problem. We will need additional information in order to troubleshoot this. Check out the following video:
I attempted to reproduce the issue against the sample RadTabControl in the following page:
I was able to automate this control without problems with the current official SP2 release of Test Studio.
You should try to automate this sample control in your environment as well. Let me know whether you are able to do so successfully.
What version of Test Studio are you using? What version of the RadTabControl are you using?
Please provide some additional information so that we may troubleshoot this and get you up and running ASAP.
the Telerik team