My suggestion for others:
Go to your GTA V directory and check if that EXE file exists or not.
If the file doesn't exist, then your problem is with GTA V. If you have the Steam version just verify the game cache to get all the files back.
If the file does exist, the problem is probably with OpenIV. Try reinstalling OpenIV.
I would not suggest uninstalling and reinstalling GTA V. That's like 60 GB you have to download again!