Duplicate Community Nickname.
|Knowledge Article Number||000038162|
|Description||I'm trying to create a new user, but I'm receiving an error: "Duplicate Community Nickname .Another user has already selected this community nickname. Please select another."|
|Resolution||If you receive the error Duplicate Community Nickname. Another user has already selected this community nickname.
Please select another community nickname. This happens because within your Salesforce.com organization, there is one user with the same community nickname.
This specific field should be unique for each of the users within the organization, not unique in the system.