I don’t recall EVER experiencing so many issues with any other Sim expansion in my life. What is stranger is that I haven’t had a single crash yet. I am used to those, I obsessively save because of it. Sometimes the sims will get frozen. Sometimes it seems like the freewill mechanic is borked, they will just stand there. Not take care of any needs, or not run off to fiddle with something. At least half the sims around town are invisible, or just under the floor. Their thought bubbles and whatnot come from the floor, they can talk to your sim, but you can’t hover over them or click on them. So, that makes it complicated to reset them if you can’t even get the name of the sim in question. Butlers act strange. Vampires get stuck like other sims and just sit out in the sun and die. Sometimes your sims “reset” themselves constantly. I’ve noticed this happening the most with dance floors. Herp derp. I’ve been having all sorts of switching active household woes. All this, with no mods or custom content.
And other times, you load up the game and it works fine for a few hours.
I haven’t been able to find anyone else with these problems while reading through various forums. It figures.