Since you have installed it thru a .OIV you will most likely have to reinstall all of the mods that were inside of the Mods folder.
But you can try these fixed:
If you use steam, open steam and go to your games find "Grand Theft Auto V" Right click and click properties
on one of the tabs i believe the 2nd one down, there should be a option to "Verify Game Files" click that.