congrats on your progress. When looking for Firmware, be especially cautious as there’s versions that lack the correct signature or are incomplete and can brick your device. Open your current one with a text editor and you should be able to get a glimpse. However, I don’t know of a way to manually confirm validity.
“VPN Error: VPN not configured” means that the phone is setup to expect a VPN configuration so it can connect to a VPN server and take it from there. Either reset your phone to firmware default or exclude VPN in the SEPMAC file. Check your SEPMAC command reference for that.
”Phone not registered” indicates that the phone has not been able to successfully connect to your FreePBX server and talk to it. Check the asterisk logs again and see if you can find something.
For the sake of being thorough:
As you are able to access the settings. Lookup the phone’s IP address and enter it in your web browser’s address bar, that’s where you get the logs once the webserver is “enabled”
In the provided SEPMAC file, “webaccess” is not showing up.
Personally, I wouldn’t touch Index of /Cisco/IOS/IP Phones/7942G/English . The server appears to be hosted in Tehran, Iran.
From briefly browsing Cisco 9971 phone configuration working example with setup tips - #47 by troy_orndoff I got the impression that they’re focusing on “No trust List” being available. That requirement should be removed once you’re resetting to firmware default.