I haven't played KSP in a while, but kept it up to date. I tried starting it today but it segfaults before starting.
All other games work, only Unity3d based games do not start.
My system is Archlinux-based, latest nvidia drivers with GTX 1070, AMD FX-8370 cpu, 16 GB ram.
I do not use pulseaudio, but do use apulse & dummy-pulse, which works with all other softwares that require it. Arch wiki also mentions it as a workaround until Unity releases something that works with Alsa.
I have also tried, verifying files, reinstalling completely, launching with -force-gfx-direct.
Player.log:
