Compatibility Report

• Name of the game with compatibility issues: Grand Theft Auto V Enhanced
• Steam AppID of the game: 3240220

System Information

• GPU: AMD Ryzen 7 5700G with Radeon Graphics
• Video driver version: 4.6 (Compatibility Profile) Mesa 26.1.7-arch1.1
• Kernel version: 7.1.8-arch1-3
• Link to full system information report as Gist: https://gist.github.com/domr01/93942b4cfaa92e157764d00218ea12d2
• Proton version: Proton Experimental

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
• [x] that I have checked whether there are updates for my system available.

Symptoms

The Rockstar Games Launcher opens and loads its sign-in page normally, but authentication fails immediately with an "invalid request" error every time credentials are submitted. Retrying reproduces the same error. The account and credentials are valid (confirmed working via other means). No network/proxy/VPN is in use, and system date/time and timezone are correctly synced.

Reproduction

1. Launch Grand Theft Auto V Enhanced from Steam.
2. Steam auto-launches the Rockstar Games Launcher inside the Proton prefix.
3. Enter valid Rockstar account credentials on the launcher's sign-in page.
4. Authentication fails with "invalid request" within a few seconds.