UE5 EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000000

I have a project in UE5, and it’s really important for me. I imported a lot of models and maps into the project, but then suddenly I ran into a problem. When I tried to start the game in the viewport (Alt+P) it wouldn’t start and threw me out and gave me the error in the title. I watched a lot of solution videos but none of them worked. I’m using UE 5.3 and all of a sudden it started happening right after and not before. So for 30 seconds before the problem there was no problem. I need urgent help. This project is very very valuable to me.

Unreal Engine 5.3