visual studio 2012 - The Debugger cannot continue running the process. Unable to start debugger

Question

I have a Lightswitch 2012 application. It's been working fine for weeks. I made some changes and F5 stopped working. When I click on Start (toolbar) it gives this error message and does nothing.

"The Debugger cannot continue running the process. Unable to start debugging"

Note: It does compile file, it just doesn't run.

If I rollback to an earlier version then it works fine - i.e. it is solution specific.

Here is a video of the current version of my solution with the problem: http://screencast.com/t/TD4RzLASO

and here is the previous version of the solution from earlier today (and no, I don't know what I changed). As you can see, at least it does something with F5 or Start: http://screencast.com/t/wX5fRDPz

Rebooting doesn't help... ;)

Answer 1

Maybe you should select start up project which can be started.

Solution Explorer -> On your startable project right mouse click -> Set as Start up Project.

I had this situation when i unloaded my main lightswitch project and other project which is dll has been selected automatically and when i reloaded my main project "The Debugger cannot continue running the process. Unable to start debugging" exception was shown, because debuger was trying to load DLL.