1. You might try turning off Origin-In Game. -- Open Origin, Select Origin > Application Settings > Origin In Game and deselect or turn Off to disable Origin In Game.
2. Try playing the game in "Offline" mode -- In the Origin Client, go to the Origin Menu and select Go Offline.
3. Start the game in Windowed mode -- In the Origin Client, go to the Games Library tab, and right click on the Sims 4 Cover and select Game Properties - In the Command Line Arguments, add the following text: -w and click Okay. If this doesn't work, try: -w und
There are other troubleshooting tips in the post linked below to try:
Crashing Issues/Stopped Working
http://www.carls-sims-4-guide.com/forum/index.php?topic=29308.msg408903#msg408903There have been reports that the new expansion Dogs and Cats have been crashing due to computer's not meeting recommended specs. So it maybe a good idea to make sure your computer meets or exceeds those. (See post linked above for recommended specs)