No source code available when debugging WP8?

Question

When I debug and step any windows phone app on my virtual machine I get the "No Source Available", "The current thread is not currently running code or the call stack could not be obtained". This is regardless if I debug on the device or the emulator.
It seems like it breaks on the correct breakpoints thou, and continuing works fine.
Stepping through server code works fine.

The virtual machine is just set up for this and only contains Windows 8 (updated), Visual Studio 2012 Pro (complete, updated), Google Chrome, Start8 and Windows Phone SDK 8.0.

Answer 1

Repairing the Visual Studio installation solved the problem.