This just happened to me, but on a grander scale. I am playing a completely vanilla game, no mods, no CC. Just had Winterfest and when Father Winter showed up, everything went bonkers. I commanded the Sims to open presents under the tree, but my game seemed to suddenly lag and started teleporting Sims around in between being frozen. I tried resetting the Sims in my household, but then they went into "T" position and stayed that way. Every couple of minutes I was getting a notification of what each Sim got in their gift, but nothing was happening. One of them suddenly had on an outfit I did not give her. They continued to teleport at a slow pace, as if the game was chugging to a standstill. This household has three young adults, a teen, two children, a toddler, and a cat. I have a pretty powerful desktop PC, so performance is not normally a concern.
So then I tried going to Manage Worlds and sent them to a Cafe, but they stayed in that "T" position, but this time so did any townies that appeared on the lot. So NONE of the Sims were moving.
I tried switching households after that to a single Sim household but that Sim was in the same position. So I did a "Save As" and quit my game completely. When I restarted and continued that save, everything was back to normal.
I do play with need cheats and the move objects cheat, but I think that's all I used. The lot I was originally playing on is a 64X64, downloaded from the gallery. I'd been playing on and off this lot for a few hours and it was completely fine, until the Winterfest holiday.
This happens to me too, I often reset them because I have ridiculous simulation lag and they'll stand there forever not doing the thing I said if I don't reset them, and then oftentimes, this happens.
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