I bought and installed Zoiper recently on my Windows 10 PC. It was working great.
As soon as I upgraded it to the Pro version, all incoming calls were automatically routed to my PBX voicemail. I can still make outgoing calls without issues.
I can see for a very short time an incoming call notification (like 1/10 second) but I never have the chance to "answer" the call.
Zoiper registers the call as follow
Missed call from Phone (anonymous)
Can't find matching codec in SDP (code: 2)
If I call from another extension internally, I get the same error.
I uninstalled Zoiper and then re-installed as the free version using all default settings. Once again I can receive phone calls.
We have this problem on 2 different computers
What can I do to investigate/fix the issue?