LogLinker:Warning: Can't find file

I had this problem, it just suddenly appeared on all versions of my project from different dates. I tried everything, deleting all cache folders for UE4 and VS, deleting the .vs files, reinstalling ue4 source build, turning off plugins.

What solved it in the end for me, was deleting the config folder! So if you get a lot of loglinker errors suddenly and c++ classes not getting found, try that!