Version 0.3.7.7 suddenly extremely broken

So, I loaded my game up today and all my mods were gone, which I found out how to solve, but even without them installed my game is extremely broken, the physics won't load, the cars don't exist as entities in the level editor, I spawn under the ground, etc. Do I just need to break down and reinstall from scratch?

 

I think you have to put them in zips

 

I got it working finally. Took a lot of time and swearing but I did it.

 

What did you do?