• We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.
If someone would be so unlucky like post author or me, trying to find the reason why EU4 doesn't launch, the problem is multisampling in settings.

edit /home/*user*/.local/share/Paradox Interactive/Europa Universalis IV/settings.txt from multi_sampling=4 to multi_sampling=0
Did you really have the problem that only launching from the launcher was broken, but launching eu4 from its installation folder was working?
 
Nope, but error messages were the same. Also, this thread was what i got when searched for my game not starting problem. So, i guess, it would be no harm to try disabling multisampling for a fellow.
 
Also, topic author has Intel® Core™ i7-9700K with Intel® UHD Graphics 630 and if you run EU4 from terminal without prime-run it will use intel video, not Nvidia.

Game doesn't work only when using Nvidia and multisampling. It works perfectly (just laggy) with Intel.