Libraries have not received the ISO cancellation message because there is no value set for the ISOSystemID customization key. To update the ISO customization keys, open the Customization Manager and review the following keys under System > ISOILLDefaults:
If a different symbol needs to be used with any ISO institution, you can enter that value into the requester override field on the Lender Record; otherwise, the ISOSystemID will be used.
Enter the ISO ILL Requester ID in the Requester Override field (if needed). This is only necessary if your institution is known to the other by a symbol other than what you have set as your ISOSystemID. When sending ISO communication to this site only, ILLiad uses the Requester Override alias as your ISO Symbol instead of the Customization Manager ISOSystemID. This field is usually blank.
For more on ISO ILL in ILLiad see: https://support.atlas-sys.com/hc/en-us/articles/360039133214-Installing-ISO-ILL