Prefabs no longer usable with update.

So, I’ve got quite a few prefabs made. But there’s an issue now that popped up with the new update;

NONE OF THEM WORK ANYMORE!!

I tried each of my prefabs, my heavier warthogs and my lightest mongoose’s. I even tried my Warships.

None of them worked like they should have.

Heavily armored warthog?
Wouldn’t drive straight and was bugging out.

Mongoose with two ammo crates?
Slowed to a crawl.

Large space Battleship with a banshee?
Unusable, utterly unusable.

Anybody else having this issue, and what might be a possible fix?