Link to the log file: https://transfer.sh/13jHjT/steam-518030.log.tar.gz
PROTON_LOG=1 generated a 600MB text log file. I compressed it down to around 40MB.
Looks like a driver bug, updated to 415.25 and the problem has gone away. Closing issue.
Reference: https://devtalk.nvidia.com/default/topic/1044264/415-13-breaking-unity-engine-games-in-wine/
Compatibility Report
System Information
I confirm:
Symptoms
Error dialog pops up with title: Fatal error in gc, message: GetThreadContext failed
Reproduction
Install Aim Hero, launch it with Proton 3.16-6