[[_oidc-errors]]
== {project_name} specific errors

{project_name} server can send errors to the client application in the OIDC authentication response with parameters `error=temporarily_unavailable` and `error_description=authentication_expired`.
{project_name} sends this error when a user is authenticated and has an SSO session, but the authentication session expired in the current browser tab and hence the {project_name} server cannot automatically do SSO
re-authentication of the user and redirect back to client with a successful response. When a client application receives this type of error, it is ideal to retry authentication immediately and send a new
OIDC authentication request to the {project_name} server, which should typically always authenticate the user due to the SSO session and redirect back. For more details, see
the link:{adminguide_link}#_authentication-sessions[{adminguide_name}].