I loaded an old C++ project (ca. 2006) into Visual Studio 2017. It asked if I wanted to do a one-time conversion. Having no alternative, I OK'd.
First it complained that /ZI and /Gy- were incompatible. I googled around and figured out kind of what that was about, and got that error to hush. Now when I try to build the project, it does not find system header files, e.g. errno.h, float.h, assert.h etc..
How do I fix it?
EDIT - Here's another clue for you all. It finds latter day include files like <numeric> without .h's.