Sims 3 Generations isn't working?

Okay, so I have a few expansion packs installed, and all of them seem to be doing fine except Generations.

The clothes, hair, and items that came with Generations aren't loading up. Whenever my sims, or if a random sim in the town is wearing say pants from Generations, their legs will turn invisible. Also, it won't let me buy anything from the Generations folder in buy mode, and the icons by the nurturing and rebellious traits aren't showing up.

However, the parents still scold the kids, they can still go to prom, etc.

I was just wondering what might be wrong with this EP and not the other ones.

I tried un-installing it so I could re-install it, but it wouldn't let me.

Thanks to whoever gives a nice and informative answer :)