Cannot load saved game

I have a game that's been going on for a while. Yesterday, I could not load the save file, but I could open it by starting a new game and then immediately select "load game". Today, that option does not work either. There's no way to access the saved game. I have validated the files and done some other cleanups, but to no avail.

I can start a new game and play, but loading my ongoing game does not work.