I can't open my restaurant, or any restaurant.

I am sorry you are having this issue. Try moving the whole mods folder to another place, delete the localthumbcache.package and then test in a fresh new save game to see if the issue remains without mods/cc there. This tests to see if the issue still remains with the mods folder completely moved rather than being disabled and with traces of mods removed with the deletion of the localthumbcache.package.