I've recently taken over a 3CX phone system from a different IT company and upgraded them from V14 to V15 and the latest SP. I'm having an issue with one extension receiving an "invalid number" error message when trying to dial out to any number. It is only happening on this one extension. When I check the events I see "Call or Registration to *dialed number*@(*SIP trunk*) has failed. *IP address* replied: 604 Does not exist anywhere; from IP:*IP address*:5060"