The same thing happened to me. I was playing offline and when I made the mistake of updating my game (I removed my mods and tray folders before updating) and the game started fine, although I didn't try to play in any of my save files, I just checked to make sure CC and script mods were on, and closed the game. I moved my cc and tray back and attempted relaunch, which failed. Stumped, I went to tik tok, google, reddit, and even resorted to chat gpt (I'm not proud of it but sometimes i need a machine to think like the machine im working with) and I went through all the suggestions it gave me. I moved my mods out, I moved all my script mods out of my game folder, I checked for last exceptions, repaired and reinstalled the game, everything it threw at me. The final possible solution was to test my game, I renamed my sims4 file in document "sims 4 copy" and it made a clean copy. I relaunched the game, mods were in the old game file, and the new clean copy was launched. made sure mods and cc were enabled, closed the game, moved my mods and cc back into the new copy of the game, including script mods, and launched. The game launched successfully, but of course with out my save files. this confirmed for me, based on the research I had done, that that I was experiencing the save file corruption most likely. I also do not own the "For Rent" pack, so it is not "For Rent" related.