My game has been doing this since I tried to save on Sept 2 a file that I last played Aug 29 (and it was fine). There is no error message when this happens. It's not the Error 0 issue. The game acts like it's saving fine, but no changes are saved. The file date/time stamp update, but the content doesn't change when you go back into the file. Doing Save As does not change anything. I don't use Mods or have CC and rarely have any glitches so this suddenly happening is freaking me out a bit.
One thing I just noticed is that this file (which I've only been playing since Lovestruck came out) has ballooned to a humongous file size compared to all my other save files (it's 220,000K whereas even my longtime legacy file of multi generations is only 18,000k, I'm starting to wonder if it has something to do with all the Cupid's Corner Sims that are downloading into the file as I've been playing with the Lovestruck features. Manage Worlds says I now have 64/150 Sims in game, which seems a high number for me. My played Sims only total about 20.
I started a new file Sept 3 as a test with only a couple of my own Sims and so far it's saving okay and the file size is only 8,000k. But now I'm afraid to open any of my older files with my legacies, because I don't want these saves destroyed and I don't know what triggered this. 😬