IDERepositoryViewer damaged or missing resources causes Xcode 5 to crash. Why?
Thanks for your post of the problem, it helped me to work out what the issue is. That offending plug-in is NOT part of Xcode 5 at all. Like you, I had this happen after upgrading from Xcode 4 to Xcode 5. I did a clean install of Xcode 5 on another computer and it doesn't have that plug-in.