Game freezes, then reverts to hours earlier

Since installing Adventure Awaits:

The entire world freezes, including the clock. The first time, I went to Manage Worlds but was stuck in the loading screen, so force-crashed. Then I could not launch the game at all. I rebooted and repaired game and could play again.

After a while, the same freeze happened. I was able to go to Build/Buy and put down some terrain paint, but there was no option to erase it or undo it. I went back to live mode - still frozen. Went to Manage Worlds. This time it didn't get stuck, but this is how my menu looked:

I didn't attempt to save so "the game failed to save" message is interesting.

After that I was able to get back into my original household... but time reverted back to the point when I first started playing. As in it rewound several hours. All the changes I'd made to the lot since opening the game were gone.

Also I was then completely unable to access the current event. I can see the Rewards panel but not the Quests. Before the freeze, I had made a lot of progress in the event, but since time reverted I'm not sure if that became confused.

I play on Mac. I have all expansions except Batuu and Strangerville and most of the smaller ones. 

I do not use mods or CC.