I have a slight problem with the sims 3?

I have never had problems with the Sims 3 until now. I have expanded my game and I'm having a serious glitch on all of active households in the sims. I am supposed to have 5 in one household but only 3 sims show up on the active sims bar. I don't know how to fix this I tried to evacuate them and move them into a new house it wouldn't let me do that. When I try to do anything with this particular family of sims my game stops responding and I have to close it. One sim aged up on the game before it started glitching and a new one was born, I saved my game shortly after but I don't think it should get rid of my sims from my active household. How can I fix this?