Legacy GM YYC compiler help

I had some trouble setting up the yyc even though I went through the pain of collecting all legacy Visual Studio versions... Once I arrived in GameMaker Preferences, set all paths, I clicked "Check". Damn, everything OK.

As I tried compiling the whole thing, GM gave me the error "Could not find file". I suspect this happens because I tried to compile a project made in GMS Standard Edition, so in the end I got it fixed by doing the following:

1. Make sure you have the paths set up correctly (8.1 Kit and VS 2015, listed as Visual Studio 11 for some reason)
2. Create a new Configuration (Middle, top of the screen, new config, select create config from default, or whatever your main config is)
3. Select that config in the dropdown menu (Its not selected by default)
4. Compile.

I still have no idea why this is, but it works and I'm happy. To whoever is seeing this: I feel your pain. It must have been a long way to find this page...