Beepants If you recover the next-newest save from before you used the cheat, is the lot still gone? And to be sure, you quit the game after the lot disappeared and before loading a backup, right? If not, please try that now, with a backup you hadn't previously loaded. The corrupt data from the main save might not be released if you only exit to the Main Menu.
Please also test this in a new save, with fresh sims and a default EA-made lot, nothing from the Gallery or your own library. If that's fine, test a different lot in your existing save. You can make a copy of the save or backup you're using before doing this so you don't damage a file you might want to use later.
