UBOAT (494840)

Compatibility Report

• Name of the game with compatibility issues: UBOAT
• Steam AppID of the game: 494840

System Information

• GPU: GTX 1070
• Driver/LLVM version: 440.44-6
• Kernel version: 5.4
• Link to full system information report as Gist: --
• Proton version: 4.11-11

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.

steam-494840.log

Symptoms

game crashes to desktop after a few seconds in main menu. Launcher not starting at all

Reproduction

1- start the game
2- press escape twice to get to main menu
3- wait a few seconds and it crashes

I am in a discussion with the developer on their community discussion board, at it looks like it is a issue on wine/proton's side:

nihilcat [developer]"
"Thank you. My theory, by looking at the log, is that NVidia library (nvtt.dll) tries to check, if you have NVidia card, but the needed function is not implemented in Wine so far.

It's bigger work that may introduce new bugs. It's too late to include it in B125, but I will try to fix this in B126 preview builds."

They are using a newer Nvidia texture compression library, which led to the game crashing on New Game start. The menu was cached, hence one could get to the main menu, but not the game itself.

Start with the attached steam-494840.log and reproduce the crash using the listed steps under Proton 4.11-11. Review the reported nvtt.dll/NVIDIA library behavior in Proton or Wine; done means UBOAT no longer crashes after reaching the main menu and the launcher starts as expected.