Just noticed that it works with Proton 9.0-4. So it's a regression.
For completeness, I am sending the log with proton 9.0-4 so it can be used as comparison.
@Patola I've been able to reproduce this issue. It's a regression between Proton 10.0-2e and Proton 10.0-3 it looks like, so one we just introduced with the latest Stable update. Thank you so much for catching this and reporting it! We will get this investigated. Also, I appreciate the log with a working Proton version. That is always helpful in case we are unable to reproduce and need a comparison.
You're welcome.
proton 10.0-2ex1 2025-12proton 10.0-3x1 2025-12proton 9.0-4x1 2025-12proton9.0-4x1 2025-12
Compatibility Report
System Information
I confirm:
Symptoms
Game doesn't start. The splash screen starts and the loading symbol starts to fade out then it freezes:
Reproduction
Just start the game.
steam-536280.zip