As I said a while ago, Visual Studio 2015 appears to have lots of pretty serious bugs.
One that probably bites me more than many people is this Save As bug. If you have a project and you select a file in that project and do a "Save As" such that the target file is also in the project then the VS2015 IDE crashes.
I tweeted about this a while back, and the Visual Studio Program Manager, Cathy Sullivan, wanted me to create a new project and see if the problem happened with it... Not quite sure why she couldn't do this herself, but anyway, here's a zip of a project created with VS2015 where there's a file called SaveMeAsTargetver.h. If you save that file as targetver.h then the IDE crashes.