I get errors from Test Studio saying “cannot access the Silverlight app, do you need any more help?” Typically this is shown and stays on the screen for a while:
[Silverlight icon] Detected Silverlight, Configuring...

Whether or not this is a bug, I don’t know, I was probably the only one complaining about the issue, I discussed it in an [internal discussion] thread but didn’t reopen the ticket for Telerik, actually I forgot to do it until the issue came back today when defining elements for a flow shape Properties popup.

I think Test Studio shall become more responsive in this respect and just do not wait for the Silverlight control to initialize – if the control is not visible or just initiated from JavaScript, it may never respond back to the Test Studio, so the whole procedure is useless.