SMS message fails to deliver and logs indicate the following error
Notification Error;  Message failed due to unknown mobile operator error
- All versions of xMatters
- SMS Notifications
This error indicates that a message could not be delivered due to an error at the carrier level. The error may resolve without intervention after a short period of time. If the error persists, please Submit a Request with Customer Support for investigation.
Consider using the xMatters mobile app. Although we continue to work with carriers, providers, and aggregators to lobby for the best end-user experience over SMS, we recommend the xMatters mobile app as a more reliable alternative.