Visual Studio does not honor include directories

I have found (stumbled) on the solution (I think). It has something to do with the character limit imposed by the OS. Although the limit should be 260, for me it falls in the below 150, see this discussion and links to it. I downloaded and unzipped the file to C:\Users\MyUserName\My Documents\Downloads\Downloads From Chrome\MyGui3.0...[and so on]. I learned quite some time ago not to try to compile projects under such long paths, but this time it completely slipped my mind as VS did not give me a warning at all and pointed me in the wrong direction. Anyway, cutting and pasting the project to D:\ fixed the issue. I am not going to checkmark the answer however until someone confirms this.

This happened to me once. It turned out the inconsistency of the Debug vs Release builds. When I modified one build, the other build was being compiled. Please set both builds with same include folders and see if it works. Good luck.