I've never had this before and now its only when I try and load one particular family the game plays perfectly everywhere else and I don't use cc. The only recent things that have happened on the lot I am trying to load is an elder died and I sent a teen sim to college using the send sims to college button which I've never done before.
I have deleted cache files but the error still comes up and closes the game on the loading screen. I really don't want to move them out either if that can be avoided. Any suggestions?

I already had to completely abandon sims 3 and go back to sims 2 when sims 3 broke, I don't want to stop playing until sims 4 comes out

You may have to move them out. I never send playable to college by the send to college button, I only use that to send townies.

In hood view you can move houses to a dif. place in the hood (do not put the house in the bin or you will corrupt your hood) and you could try that first but I think you will need to move them out to save the family, you may be able to move them back in if you can load the empty house.