Worlds Gone, Game Treated As If No Saves Present

UniteSim​  Then I'd go right to a clean uninstall and reinstall of the game (and the EA App for good measure).  While there are intermediate steps you could try, they probably won't take any less of your time unless the first one happens to work, and a clean uninstall will address everything on the install side at once.  Here's how to run one:

📓[GUIDE] [PC] How to Clean-uninstall Sims 4 | EA Forums - 12636503