When I debugging in VS2013 update3, msvsmon.exe crashed when hit at a breakpoint.
It shows \"The debugger\'s worker process (msvsmon.exe) unexpectedly exited. Debugging
I was using the OzCode debugger extension. Unfortunately they don't have a way to completely disable the extension - you can only disable certain features - so I had to completely uninstall it to confirm it was what was contributing to the crashes.