This is a bug with all special NPCs showing up on lots. It started with Pets when the strays or especially the wolves showed up. On a machine (now old) back in the day, my game would lag out and freeze, it has a lot to do with the processor and video card. And 3D shaders. This was on their end, not my machine. I removed the witches from showing up on community lots and owned business lots with a mod. Even on my machine today, I still see a slight pause with the wolves popping into the portal on home lots. Reinstalling won't help this. This is how they determine how much they think of your video card. Back in the day even midgrade video cards were considered low end by their code.
There are cheats for the Config files to go in there and change the number it rates the video card. If I can find some of those instructions or you can google it, I might be able to help. But best suggestion is to stop witches from showing up with a mod.
