Hi @KarensJohnny I got the same error but I think I have solved this. I have the original GTA 5 game from epic games and for installing the mods I downloaded the crack version, so when we install openIV it searches the system for the game folder in the C:\Program Files and the loads it.
If you have another a copy in any another directory you need to change the game folder directory in openIV from Tools->options->Game->GTA V Directory there you can see change directory option. After changing the directory you need to restart the openIV then you need to install the options in ASI manager. This solved the issue for me so try this and if it doesn't work please reply to me I will tell you what other changes I have done.