I recently experienced a problem where I couldn't open Visual C++ projects (.vcxproj) after I copied them to another location. When trying to open the projects, VS 2015 would give me nothing more than this "extremely useful" error:
That is some talent, right there. That must have taken a lot of work to get this right.
After trying various things, and having researched this without success for a few hours, I finally got the idea to try opening the projects in Visual Studio 2013, instead.
Behold: VS 2013 actually displayed a useful error, which informed me that my projects had
Importdependencies that I forgot to move.
So, yeah. If VS 2015 helpfully tells you that "one or more errors occurred" try VS 2013.