Could not load main init file: config/main_init.cfg

[Guest]

It's because you have a Mac.

I am assuming you are running 10.9.2 or above (I use a Windows, so I don't know if there are any new versions out) Mavericks. There's a problem with Amnesia: The Dark Descent in terms of locating that file.

There are a few threads however which may help. This is one of them: https://www.frictionalgames.com/forum/thread-23953.html

I've tried that thread, but the issue is I can't use that as a solution because I downloaded it from steam so the terminal solution does not work.

Thank you though!