I was trying to sort my rigs and delete most of them with the system option 'delete all rigs expect favorites'
I went from 1500 rigs to 300 but in the meanwhile I lost 8 personal profiles I add done one day ago (Hopefully I made a partial backup prior to this !).
There was a warning "delete all rigs except my stuff (favorites/snapshots/own rigs)" , but only a few of my own rigs were available after the operation , I lost all the profiles I had just done .
Be sure to backup before doing the big deletion.