I'm sorry you are experiencing this problem. RadWindow use IFrames. These IFrames contain a BaseURL that needs to be adjusted in order to work properly on different environment. The default is to do an exactly match as recorded and that is the reason your test to fail when it tries to find the RadWindow. It can't find an IFrame that matches the URL it was recorded against.
To fix this you need to change the BaseURL property of the IFrame node to use partial URL matching(see screenshot).
You can also check our KB article
on "Running a Test Against Multiple Environments (Using BaseURL)".
Hope to here from you soon!
the Telerik team