Duplicate User Found

Customer Managed Applies to customer-managed instances of Alation

Applies from version 2022.3


Some users report that when they try to log in to Alation, they receive the error Duplicate user found. Contact your Administrator to resolve this problem.

This error can occur with any type of user authentication: LDAP, SAML, OpenID Connect, or basic.


From version 2022.3, Alation no longer supports case sensitive usernames. All usernames are treated as case insensitive. For example, usernames like Alvin.Lucas and alvin.lucas are considered identical.


In releases prior to 2022.3, case sensitive usernames were supported, and usernames differing in the use of lowercase and uppercase letters only were considered different usernames.

Starting with 2022.3, username duplicates will prevent users from logging in. The duplicate user found error points to the presence of mixed case duplicate usernames on your Alation instance.

Alation provides a special script to help de-duplicate usernames. Refer to De-duplicate Mixed Case Usernames for information about this script and for steps to run it on your instance.