After upgrading my MythTV server from 0.25 to 0.29 as described in MythTV on CentOS 7 I found that the last tab for MythWeb, “Backend Status” was giving me a:

404 Not Found

It really had me stumped and then I found what was the problem for me. During the transition from my old server to the new one I had both MythTV servers running at once and so turned off UPnP. It appears that was the problem.

I was running it as a service so I ran:

systemctl edit mythbackend.service

Which opens up the service file in nano. Simply remove the “–noupnp” section, save it and restart the service.