Hello @AnthonySchliesman, we're tracking issues with games run with Proton in the Proton issue tracker. Also, we're using one issue report per unofficially supported game title, so I've gone ahead and transferred this issue report to https://github.com/ValveSoftware/Proton/issues/9171#issuecomment-3599060624.
@kisak-valve I left out a couple of other key details with the original post, for which this could potentially be pulled back to steam-for-linux:
Apologies for leaving these details out of the original post!
Your system information
Steam Stable: 1763795278
Steam Beta: 1764106918
Arch Linux w/ KDE Wayland
Yes
tar -zcvf ~/Desktop/steam-logs.tar.gz ~/.steam/steam/logs]steam-logs.tar.gz
Nvidia
Please describe your issue in as much detail as possible:
When launching into Monster Trucks Nitro (16620), the game fails to register the Product Key, resulting in a 'proper host system' error message (see screenshot). This can be remedied by editing the license key into a .reg file/modify registry to: HKEY_CURRENT_USER\Software\RedLynx\Monster Trucks Nitro\LicenseKey. This does not need to be done on Windows, as the key is picked up immediately on first launch with a 'successfully activated' message.
Steps for reproducing this issue:
steam-16620.log