I looked through that thread which seems to imply it is a browser problem...
I'm using Firefox 56.0.2 - Build identifier: Mozilla/5.0 (X11; FreeBSD i386; rv:56.0) Gecko/20100101 Firefox/56.0
The main problem is being able to use any program to watch tv... I guess I haven't quite yet got the hang of it.
When I select Play from a list of services, Firefox downloads the link and attempts to play the link via VLC. VLC opens up but I am unable to play anything. Having said that, I did manage to make a recording and was able to play that via VLC.
Apologies if this doesn't make much sense, but I am only just starting out with TVheadend which seems to be a very powerful program with enormous capabilities, so inevitably has a steep learning curve andI accept that it will take a while to get the hang of using it.