Update: Seems like I get stuck no matter what, re-pasting a old backups Default layer fixes the problem for maybe 15min before the error shows up when trying to go into Camera mode.

Update: Copy pasting old backup default works as a temporary fix, but error might show up after awhile. The only thing I tweaked/touched in the Default layer is the TimeandWeatherManager. It's not solved yet then.

Update: Nevermind, problem is back after ive only placed down some concrete prefabs and adjusted the weather a little bit.

Solved my problem by copy pasting a Default layer from a older back up save to my new save. Not sure which entity inside of my default layer caused the problem. But atleast I know somewhat where the issue was located. You may lock close this task.