I have experienced similar, since the last update the game failed on revert to launch or hangar, after 5 steam removals and kerbal reinstalls and days of some people attempting to help but others just flaming me, as it works on their system, I have concluded the same, the game is broke. hope you have more luck than i did getting it going. Sad that on a machine that runs wow fine at good settings and civ 6 at max wo issue, Kerbal is failing. So 0.90 is broken in someway if so many peoples games have started crashing.
