@lamb.troy Thank you for contacting us. When a user receives this error message it is typically because the phone numbers have not successfully gone through the TCR registration process. Complete that process and be sure to associate all relevant phone numbers with your TCR campaign to enable them to send AND receive SMS. 

To confirm that this is indeed your problem a simple thing any user can do is download the RingCentral desktop application, navigate to the “Text” tab and try to send an SMS. If you cannot send an SMS from our primary desktop app, then you will not be able to send a text via the Unified CRM extension. If however, you can, then something is wrong with the Unified CRM extension. We recommend closing the extension’s main window, and re-opening it to see if that resolves your problem. If not, please contact us here and someone will assist.