Getting "PAM-UI-1003: Unauthorized" error on PAM GUI.
PAM uses PHPSESSID cookie for session management.
PAM User's PHPSESSID cookie value gets stored in an internal mysql table which will display user session at "Sessions -> Manage Sessions".
When a user session gets timed out or logout, the record will be removed.
If a request is received with a PHPSESSID cookie that is not present in the table then this error will be displayed.
User session has been terminated or did not exist.
Ideally the "Timeout Warning" and "PAM-CMN-009: Your login has timed out." window should popup but this is not always the case.
PAM User simply need to re-login as previous session has been terminated.