Body shop crashes on launch

Try deleting your thumbnails in the files. That might have been one reason you lost one Sim in bodyshop. Those thumbnails sometimes don't show the right Sim, or not at all. They do get corrupted. Also delete your cigen cache.

When you say thumbnails, I presume you mean the ones in Simpe? I didn't know they could be deleted. Where do I find the cigen cache? Yes, I'm making notes to be sure I get it right when away from here and in the mess on the other machine. There are about 5 or so sims from the old machine - my favorite 'gang' I'd play constantly in every neighborhood - that I'd like to bring over to UC. Am using the method given over at Scribal Goddess's topic on avoiding corruption.

No, I don't mean inside SimPe. I mean the thumbnails and cache files inside the TS2UC Document files. Go to your documents, EA Games/TS2UC
You will probably see a cigen package (cache files) near the bottom it's a good idea to delete those offen. Along with the Accessory cache, and you will see a file called Thumbnails open it and delete anything in there but especially CASthumnails package. The game regenerates all of these things every time you play. They all become corrupted and bloated if you use bodyshop or CAS often.

Show by date and remove the last of them and maybe re-export the one that isn't showing up.

Good thing I asked! Thanks!

Have done the suggested executions and BS still crashes as before. Saw a 'groups cache'. Should that be deleted as well? Something is very broken, and I have no idea what it is, let alone how to fix it.

Is there a way to reinstall B.S. without uninstall/reinstall the whole game?

Yes, you can delete the group cache file. Try pulling your saved Sim folder that contains your saved Sims you have built in bodyshop and see if that stops the crashing. If that fails then it's time to pull your custom content. If you have been working on a lot of projects in bodyshop such as retextures and recolors you might think about moving the Projects file to desktop to speed up reloading.

Thank you. Will start the deleting, moving & testing process as soon as I can. Am suspecting the root may be the file of the one sim that isn't showing up, but have no idea which of the 3 files it is.