YouTube troubles on Pale Moon 26.5.0. Ubuntu

[Lightice]

Hello!

After being recently forced to reinstall the browser, I've had an odd problem with YouTube: the HTML5 player no longer displays any other resolution options than 360p, forcing me to use the flash-player, which I find endlessly distasteful. I'm still running 26.5.0 until my language gets localised, but it never had any trouble with YouTube before the reinstallation. https://www.youtube.com/html5 shows that the browser apparently doesn't support H.264, WebM VP8 and Media Source Extensions, all of the sudden. How do I get these old supports back working?

EDIT:
According to about:config, all these things should work.
"media.webm.enabled" is set to "true, as is "media.gstreamer.enabled". I am stumped.

[trava90]

You need the GSteamer 0.10 packages. Note that MSE has never been supported in Pale Moon prior to version 27.

[Lightice]

You need the GSteamer 0.10 packages. Note that MSE has never been supported in Pale Moon prior to version 27.

So, in other words, my distro removed it while I was updating everything else? That's a bummer. I've been trying to look around, but I don't see any easy way to reinstall the 0.10 package. Is there a way to just get it from some repository, at this point?

[trava90]

It depends on your distro. It's also possible that something happened to your profile when downgrading from 27 back to 26.5. Try using a new profile.

[Lightice]

It depends on your distro. It's also possible that something happened to your profile when downgrading from 27 back to 26.5. Try using a new profile.

I'm running Ubuntu 16.04.1. I looked up and installed various GStreamer 0.1 packages, but to no avail, they seem to be doing nothing to the problem. Looks like I'm in for a yet another reinstall...

[trava90]

GStreamer 0.10 is very old and many distros are dropping it in favor of GStreamer 1.x (which Pale Moon 27 is using). there used to be a PPA available for older *buntus, but I think it was taken down.

For what it's worth Pale Moon 27.1 will be dropping GStreamer for video support in favor of ffmpeg.