[Michael Butler]

I know it's time consuming, but  you can rename the my documents AC folder to "AC old" then restart the game and it will write a new one that is active and fresh...this is all your personal settings....then you can add old folders 1 at a time to see which one is the problem or just leave it like that and redo all you settings again. Then if you want to revert back to the old one, just rename the new one NEW and rename the old one back to "Assetto Corsa". either the problem is in that folder or the install folder. Eliminate Content manager as a problem for now...get the game working by itself, then use CM.