Hi smallerstone, Thank you for your question I understand that there is an issue with playing a video, and the error is Error loading media. It looks like the format of the video is an mp4 and that the page also have an option to download the video to play locally in the meantime.

I also did some experimenting if you double tap on the video player a bar at the bottom of the video will come up. I till have a gear, and a full screen icon. I could not get the full screen icon to work, but I did try to select a different media quality that was present when I double tapped the gear. It also gave me an unending loading bar when I selected 280p.

It also loads in flash on the desktop site, I wonder if is the player. For your mobile device does it support Flash?

My mobile support Flash. I can play the video in this web when I change it to desktop mode, but I can watch it in mobile mode in other broswer such as Chrome.

I filed a bug on this with as much information as I could find. If you would like to be updated on it, you may need to register and cc self to the bug. https://bugzilla.mozilla.org/show_bug.cgi?id=1056971 In the meantime if any other examples where this happens please add the url to the bug.