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
In my case, it was caused by a VPN software. It changed my hosts file and my localhost was not 127.0.0.1 anymore.
hosts
localhost
127.0.0.1
So check your localhost in the hosts file (e. g. %WINDIR%\System32\drivers\etc\hosts) and make sure it is 127.0.0.1.
%WINDIR%\System32\drivers\etc\hosts