So I’ve tested this and it only seems to crash when adding the while jumping condition
Indeed, for now make sure to only cut/paste conditions to AND conditions instead of dragging them.
I’ve only crashed with the jump condition so far and I’ve been dragging a lot of stuff to ‘&’ conditions. Cutting and pasting and also just adding the condition doesn’t make it crash. While you’re here, I would like to get the opportunity to thank you, the creator of GD. I have tried a lot of game development applications and only yours seems to make me stay and finally finish the game I’ve been dreaming to create. Thank you so so so much! Kudos to you 
Had the same problem with OR condition. So I just copy/past condition instead of dragging it to prevent the crash.