Ok So i've changed all my downloads since creating this sim. I extracted him from the game, and then cloned him in body shop to give him some new hair and other cc. when i clicked the hair tab no hair showed up. Not even the maxis stuff. I clicked a different color of hair and instead of switching to that color both tabs highlighted. Does anyone know how to fix this or why it's doing it.

PS: With other sims that i clone the hair works fine as well as creating new sims in body shop. It's just 3 of the sims. (its all the sims that lost their hair meshes. If that means anything.)

When deleting content that is still on a saved Sim, lots of bad stuff can happen. This is why it is always important that if you delete content, you must make sure no one is currently using it.

You could try clearing your cache. That usually works for me when body shop doesn't load something. If that doesn't work, try re-loading the meshes that they use, change them in body shop to a maxis-made hair, and THEN delete the meshes. If that doesn't work, you may just have to delete the sim.

Have you tried opening the sim in the in-game CAS?

Sorry for the big bump, but I have the same problem when I choose not to install the CC hairs from the packaged Sims I've downloaded. Even cloning the Sim in Bodyshop didn't work. In even older threads, HP referred to a Sims2Wiki link, but that's broken and not properly archived.

Is the only workaround installing those hairs temporarily (place them in separate folders) until I've cloned those Sims with different hairs?

I think the only proper workaround is to install the hairs temporarily, yes. If you want to fully fix the sims in Bodyshop before putting them ingame this is the best solution.

Non-existing hairs won't show in Bodyshop, and they'll bork the hair selection there.

I've seen a few prople posting that selecting a new hair works in CAS, but I'm not entirely sure if it works (haven't tried), and not sure if it would work every time. It is posible the sim could be a bit borked, too. Could be worth a try.

Selecting a new hair works in CAS, I promise. I have more than one sim bin sim who's bodyshop bald. They show up with a random hair and you treat it normally. It's only in bodyshop and the thumbnail that the scalp is missing.