Game ran fine until like day 280, only noticable thing that may be connected to the bug is that i trapped a Puft to farm slime. After some time it simply was gone. I had 3 of them flying around, now there's only 1 left. Since then the game keeps on crashing at different points, sometimes it takes 5 minutes after loading, sometimes less then 1.
I will start a new game and see if this happens again.
pufts started disappearing, also always happens when trying to get my water purification with steam working, but can't confirm