OpenIV for GTA 5 is a necessary PC modding tool without which you can't really install a number of mods.

GTA 5 mod install guide: How to install and get GTA 5 mods on PC Here's how to tinker with one of Rockstar's greatest games by finding and installing mods.

They now have to install all three options: ASI loader, OpenIV.ASI, and openCamera. If players get a "create mod folder" prompt, they have to select the "Yes" option.