FileNotFoundError: [Errno 2] No such file or directory: 'portal2\\gameinfo.txt'
When making a map in hammer, and trying to play it this error appears. I think it's a problem with postcomplier.exe, because unchecking that option in Run Map [Advanced] shows no error. The entities are broken then though.
I also add that I followed every single step on the wiki.
Okay, it broke because your map isn't saved in sdk_content, and so it couldn't determine where the Portal 2 folder is. A srctools.vdf config should have generated next to your VMF. Open that up and set gameinfo to the full path to Portal 2/portal2/.
There is no such file in my map directory. There is srctools.vdf but it's in the Portal 2\bin\postcompiler, but changing any value there gives no results as it resets.