Sims 4 lots appear empty after update

I have been playing the Sims 4 for a few months, and I've had an issue since the new base game update came out a few days ago. I can see the houses when I view a world from the map, but when I click on a lot (in build or live mode), it shows up completely blank. The sims that live there show up, but the terrain and house are completely gone. 

This happens in my current game, but when I started a new game, it seemed to be working normally. 

I play on a MacBook Air running on 10.14.5 and my game is fully updated. I use no CC or mods and own a few packs, but none purchased within the last few weeks. 

Is there anything I can do to save my game? How can I fix this? Thanks!