Corrupted Memories? Help needed

My new nightlife neighbourhood has run into trouble in the form of a 2nd gen teen suddenly getting all her memory pictures blanked out. I was alerted to the memory problem when she and a group of townies all suddenly began talking about the squiggly lines (curtains I think some call them). I've always thought that the curtains thing happened when they were talking about a dead sim who had somehow become corrupted, usually in overpopulated nieghbourhoods right? This neighbourhood holds just over 200 character files but no-one has died yet :/

I used deleteallcharacters before creating the founding sim, then used the testingcheats to create all townies/npc's. I have noticed though that there are a lot of duplicate sims but with different names. Mrs Crumplebottom was bitten sometime during Sarahs (the affected teen) visit to the community lot, though I didn't see it happen. There was a minutes freeze when Sarah influenced a vamp to bite another of the group, I honestly though it had crashed for a moment there but it was fine after a while, it was during that moments freeze that the Count & Mrs Crumplebottom showed up on the lot, the freeze itself could have been because the Count was biting her at the edge while my attention was on the influenced vampire. Anyway it was shortly after this that I sent my sim to another community lot and it was there I noticed all the sims present were talking curtains and my sims memories were all blank green & red.

The memories still have the associated text when clicked on, it's the pictures that are missing. Any information on why this happened, how to fix it (if possible) and most importantly how to prevent it happening again would be most welcome. The game is currently on pause at the community lot while I try and search up some answers.

Edit:

I sent her back home to check on mum & dad and they are the same, her brother in the college dorms also has all blank memories.