Visual Studio 2015 project no longer runs in debug mode

Question

This is what I get even when I run in the Debug configuration:

The way I got this to show was by enabling "Just My Code" and warn if there

Answer 1

After viewing the link by Patrick as a comment to the question, someone noted a workaround which was to stop the site in IIS Express. I was able to prevent this same problem from arising by doing just that after stopping the debugger in Visual Studio.

However, I was looking into it more, and I believe it could also be related to the 'Edit and Continue' setting for the debugger. When I disabled that in the menu Tools → Options... of Visual Studio, I no longer had the problem. But then that would prevent you from using the Edit and Continue feature, so I am not sure if that's worth it to you.

Menu Tools → Options → Debugger → Edit and Continue (scroll to the bottom of the General list) → uncheck the Edit and Continue checkbox.

I also experienced this suddenly after installing Update 1, but it could just be that I had this setting off in the first place...I am not sure though.