Sims won't/can't cook

For some reason since a little before the announcement of the love struck pack, my sims won't cook. They pull out the stuff from the fridge and then they stop and put it down on the counter, and whenever I try to get them to resume the action they will pick it up walk to a counter, then just stop, and put it down, and will cancel the action without me touching/canceling the action. I have to completely shut down the game and re-open open the game to get it to work again.