Entire household stuck, game gets stuck on loading screen on exit

I had the same problem, reset Sim doesn't work. I went into the other neighbourhood (don't know which you're playing in so obviously whichever one you're not.) I sent a sim from this neighbourhood to visit my frozen sim and chatted to them, went back home, saved the game to main menu and then opened the original game. Sims were no longer frozen, not sure what to do if both neighbourhoods freeze though.