It is my Rabbit Hole challenge file, and yes, I think they may be bugged. I looked over my notes I've been keeping and I got the fridge around the same time both sims turned invisible. I reset them and they reappeared, and I thought that was the end of it, but maybe this is a result of it too. Not to worry, considering the problems some people are having with that challenge, my sims throwing up is minor, plus I'm only 1 1/2 sim weeks away from finishing so all is still mostly well!