When creating a new user a Whoops error is displayed stating that the username is already taken. I have checked and there are no other occurrences of this email in the system. Why is this being displayed.
Usernames within workfront must be unique. There are 2 reasons that this could be caused. 1) Go to the People tab and add a column for username to the view. This can be done by going to VIew > Customize View > + Add Column > Select USER Username. This will give you a view to look at the usernames to find the duplicate. 2) The other cause for this would be the username is used in another instance of Workfront. This is commonly the case for consultants that work with other companies who use Workfront. The solution for this issue is to use a different case for the new user name. ie. if email@example.com is the duplicate you could use JohnDoe@domain.com for the new user.