Where the game can be installed
On first launch Rageon readsC:\Program Files (x86)\Steam\SteamApps\common\Grand Theft Auto V. It does not look for Rockstar Games Launcher or Epic installs. If your game is anywhere else, choose the folder in First setup.
Mods are not required, but extra folders with loose .rpf files, models, and textures are read together with the game. See Settings: App.
Troubleshooting
Error: …
Error: …
The scan failed and the status bar turned red. Check that GTA V folder in Settings › App points to a GTA V Legacy folder that contains
GTA5.exe, then click Save and scan. See Troubleshooting.