I am trying to make a sales rep inactive because I have no idea how it became a Sales Rep to begin with. He only appears in three invoices dating back to 2011. However, it is making QB crash constantly. I did the Verify Data as you say and then ran the Rebuild (three times) and I still get an error saying that the Sales Rep is duplicated. I am attaching a screenshot of the log. When I try to make him inactive, QB crashes. I'm on QB for Mac 2020.