Has anyone got any ideas on this one? I have just set up the trial version of 3CX and registered a SIP trunk with Voiceflex. I can receive calls with no problem, but cannot make outgoing calls. In the logs I get a '404 Not found' error, so I contacted Voiceflex support to ask if they had any guides to configuring their SIP trunks on 3CX, or why I was getting this error. The response I got was: Does anyone know how to get 3CX to send the invite again after the 404?