The log says you're using proton-3.16-9. Maybe try with the latest release instead?
Newest Proton 4.11-1b, same result, wish I knew what to look for in the logs.
steam-268130.log
Something somewhere is seriously broken so I'm doing a full wipe & reinstall of the entire system, the world shall hear from me again.
I'm back & everything is working as intended, not sure what broke before so I'm going to leave things alone & see how it goes.
Looks like your problem was with libsdl2 but I've got no idea why.
Unhandled exception: page fault on read access to 0x6977307b in 32-bit code (0xf42d7645)
...
Backtrace:
=>0 0xf42d7645 in libsdl2-2.0.so.0 (+0x35645) (0x0032f588)
Unhandled exception: page fault on read access to 0x0000011a in 32-bit code (0xf429c645).
...
Backtrace:
=>0 0xf429c645 SDL_GL_UnloadLibrary+0xbf55() in libsdl2-2.0.so.0 (0x0032f608)
I managed to have 3 different versions installed at the same time, don't ask me how cause I haven't a clue, that with the broken drivers made games that should work stop working, I wiped the drive & started again with a fresh install of Ubuntu 18.04, so everything is back to how it should be, I forgot the golden rule, if it ain't broke, don't fix it.
Sadly, that means not updating anything either but we can't have everything - security updates are of greater importance than breaking stuff with how things are today.
If it ain't broke, break it for security lol
The game was previously working but since updating to the latest Kernel & drivers the game crashes on hitting the play button.
steam-268130.log
https://gist.github.com/lucifertdark/584c14275612e8e3c4a8070d428d8a02
Hopefully it's something simple that I can fix.