When a user's credentials are changed internally, whether it is your Active Directory listing or other source of user management, the changes must also be made in Agile Central to match. If changes are made to only one location, when a user attempts to login through your SSO URL, the authentication will fail to match accounts and prevent access.
Jane Doe has recently changed her name to Jane Smith. Previously, her email address was email@example.com and now has become firstname.lastname@example.org. Her IT Administrators made this change to her account within Active Directory, but the Agile Central Administrators have not updated Agile Central, so she is still listed as email@example.com in Agile Central.
Attempting to login with firstname.lastname@example.org through her company's SSO URL, she is unable to do so, and cannot access her Agile Central account.
Her Agile Central Administrators will need to login to Agile Central and update email@example.com to firstname.lastname@example.org.
After this change is made, Jane attempts to login again. She is able to successfully access the Agile Central subscription.