UnrealBuildTool: include cannot be found

Hi, I created a C++ Blank Project and added external .h and .cpp files. I can compile the project in MSVS, and “Play” in the editor works as well, but when I try to “Launch” it, the output log complains that it cannot find the included files.
I checked the project settings, but couldn’t find out where to add those includes outside of MSVS. Google didn’t help me either.

What am I doing wrong?`
Thanks in advance.

No one any idea?

Could you post the log?


I hope this helps. Thanks.