Compatibility Report

• Name of the game with compatibility issues: Warhammer 40,000: Space Marine 2
• Steam AppID of the game: 2183900

System Information

• GPU: NVIDIA GeForce RTX 4080 Max-Q / Mobile [Discrete]
• Video driver version: NVIDIA-SMI 610.43.03
• Kernel version: Linux 7.1.5-1-cachyos
• Link to full system information report as [Gist]: https://gist.github.com/Ferrum115/4dcf1424711ba41688ac132b37c52b04
• Proton version: Proton 11, proton-cachyos-11.0-20260703

I confirm:

• [ ] that I haven't found an existing compatibility report for this game. (completely different problem + old[like, 2024 old])
• [x] that I have checked whether there are updates for my system available.

Proton log (I closed the game manually before the crash):
proton-log-2183900.zip

Symptoms:

Mid-mission game throws crash message, then freezes until being closed manually. No freezes/lags/multiplayer desync/graphical artifacts before, just crash window out of the blue. Character is controllable around a minute after, then the game freezes.

Reproduction

1. Install CachyOS latest with hyprland
2. Run Warhammre 40,000: Space Marine 2
3. Enter any multiplayer lobby
4. Play the mission(s, you can complete multiple missions before the crash, but the fastest way to replicate is Siege mode)
5. Wait until the crash window, looks like this: