Just wanted to update saying: it worked! Yay! I am so happy to be back with my sims. The 3 sims are back to normalcy! I will still play this 'hood cautiously, of course, in case this has been a warning that its death is imminent. But in the meantime I will just enjoy this 'hood & family. THANK YOU @Chris Hatch!! I'm beyond grateful for your help! :lovestruc

Also don't forget to backup that folder and store it in an archive for future use. That way, even if cautiously playing it, if something goes wrong you'll have a point in time to restore your game from.