Sims 3 doesn't respond [Closed]


So, I have had the Sims 3 since the Into the Future expansion pack came out. It was working completely fine; until I bought and downloaded the Sims 4. I never really noticed until a while ago. It opens just fine, you can do CAS, but once you've been in the game for about 5 minutes the screen goes black for a second, then the game returns to normal. Not even 10 seconds later, it happens again. The second time a window pops up saying "The Sims 3 has stopped responding" and closes. Does anybody have experience with this and know how to fix it? Thanks.