SRoberts, I had this problem, too, but was able to revert to my .backup file. Wonder why yours didn't save a .backup.
Another symptom I experience with this was that 2 of my sims were assigned different, random, computer-generated names everytime I loaded the game! So of course resetSim didn't work, because the cursor thought my characters were Bobbly Elmore or Clara Elder.
I tried many, many things to try and fix/work around this, but nothing worked.
Not very helpful, but you're not alone!!