This is a weird one. I have a C# Class Library project within my solution. If I open a .cs file within this project, the Project drop-down on the c
.cs
Project
After trying all the other offered solution, what worked for me is:
.gitattributes
*.xproj text eol=crlf
So that my VS2015 xproj style .NET Core/Standard projects worked again.
Turned out that my git was putting UNIX style EOL, which was confusing VS.
git