Save file reverted to old save on its own.
I am not sure when this happened as I've not played this file in a few weeks. (i think I last played in June, a little while after Eco Lifestyle came out). it is my main legacy file, so I wanted to play it with the new stuff pack. however, after loading the game, I realized the save is VERY old. for example, the last I played, my 2 kids were both young adults, and my main house had an entire overhaul in the yard. all of my pets were dead as well. the file that loaded, however, was one where my younger kid had just aged up into child, ly yard was bare, and all of my pets were alive. (to give you some insight on how long ago that was, I play on normal lifespan.)
I also checked to see what save slot it was, and in the savegames folder, that save slot's oldest save is from April 7th. I DEFINITELY played a LOT since then and on several different save points. there is no way it's just a matter of I accidentally didn't save a game, because I remember saving and loading the same file several times since the new expansion pack. I also use MCC command center, which auto-saves every few minutes. I tried without any mods installed and still nothing. it just decided to revert this one save and I don't understand why. my only guess is it happened after the update or it happened when I reinstalled MCC Command Center. it's Bazar and I have no idea if anyone can even help, but I'm willing to try anything if it means not having to redo like 30+ sim days.
more info: I checked my recycling bin, it wasn't in there. although I never open the save games folder so I dunno how it could have been deleted.