What lifespan are you playing on? Also, are you the only one playing on that particular computer with the Sims? If there are other people, they might be changing the lifespan and it stays that way for all the game files until someone changes it back. For example, let's say I play on normal lifespan. I save and quit and my brother plays. He likes to play on epic so when he gets on after me, he changes the settings to make the lifespan epic. When I get back on, I have to change the settings BACK to normal or else I'll be playing on epic.