We have a user that started being prompted for his credentials the other day every time he launches Outlook 2016. Typically, that seems to occur if the user is locked out or has an expired password, neither is the case here. In the credentials window, I can click on Cancel and then Outlook displays the Needs Password in the lower right corner. If I just double-click on Needs Password, it connects to Exchange. I've looked in Credentials Manager but there is nothing being stored there. Is there something else I can check?