I ended up solving the problem. My MainMenu map was causing the crash. When I exported only my testlevel and set that to the startup-level, I was able to run it.
I created a simple empty level and tried that with my menu and it worked, clearly something in my test level was causing the crash.
Basically if you encounter a problem such as this try to slowly cut out everything that could be causing the problem. Start with an empty level only, then try one of your levels, if the empty one works but not your level then it’s something in the level causing the issue.
If someone can still comment on the weird warnings I’m getting it’d be appreciated.