We have seen this happen a couple of times. Users are not sure how they get there, but doing a reset fixes the problem. You can do this by logging in as them (or have them navigate to address), then in your address bar type the following:
https://yourDomain.my.workfront.com /resetUser Seeing this here, maybe I should go in and create a ticket. But, I cannot establish a story of how users are getting this to happen. Dale Whitchurch Arthrex Inc