Editing and continuing the slow work of Visual Studio 2015 in a C # Winforms application

Question

Recently, my company upgraded from Visual Studio 2012 to Visual Studio 2015. Our main application is a large C # winforms application.

In 2012, we can start printing at the breakpoint, and almost instantly start editing the file. However, in VS2015 it usually takes a minute or more before we can start making changes. Often, the Visual Studio GUI will show (not responding) during this time. After the changes are ultimately completed, it usually takes another 30 seconds after we continue to work before the application becomes responsive.

Several members of our team have this problem. What can cause this behavior?