[2021] Game crashes when pressing play(linux)

Has this game ever worked on this machine? Or never yet?

What happens if you run the game's executable directly from a terminal command line - what output do you see then?


Please attach here your Documents/Paradox Interactive/CK3/pdx_settings.txt .
From your Documents/Paradox Interactive/CK3/logs/ folder, attach here system.log , error.log

Also in Steam please click on Steam-Help-System Info, and paste everything there into a text file and attach that here.  

I've never seen anything like this in Linux before:

Video Card:
Driver: nouveau NVA5
Driver Version: 3.3

What actual video system do you have? If it is an nVidia, can you try their proprietary driver for it please?
Download Drivers | NVIDIA