The Frontline Absence Management system (formerly Aesop) is updating and is requiring a new alphanumeric website username and password to sign in instead of using a numeric user ID and PIN. Third-party systems, like SubAssistant, can't use your new alphanumeric username but will continue using your phone login ID and phone PIN.
This means you must enter your 10-digit phone login ID and your 4-6 digit phone PIN when linking an Absence Management account to SubAssistant. Even though you cannot access your account using your old user ID and PIN anymore, SubAssistant still can.
How to find your phone login ID and phone PIN
If you don't know your phone login ID or phone PIN, you can find it in your Absence Management account under Preferences (gear icon) > Phone Credentials