Sims 4 Mac: Lost active households

I last played the Sims about a month ago. Today when I loaded the game, my active households were missing.

I can see the families I've created in the gallery, but it's as if they've never been played. If I load them into a new lot, save, and reload the game...it still shows no active household. Yet it displays a duplicate of that family in the gallery.

Interestingly, in the /Documents/Electronic Arts/The Sims 4/saves folder, I can see a record of my game from last month, yet the game doesn't seem to recognize it.

Any ideas of what may be going on here?