Firefox not displaying YouTube videos

I’ve just started to have problems displaying YouTube videos in Firefox.
Unfortunately I can’t tell whether it was the result of the last round of updates, or a reinstall that I did because my root partition had become too small so that every other main round of updates ran out of disk space (what seemed a generous allocation nine years ago is barely adequate now!) as the latest update arrived between the install / update and re-booting into the new system.

Anyhow: Attempting to play a video on YT either plays of a few seconds and then shows a “waiting wheel” or just the “waiting wheel”. I don’t think it can be a connectivity problem as the videos can be downloaded with youtube-dl & played.

Any ideas?

System: Manjaro X86-64.
Kernel: 5.14.7-2 (64bit)
Firefox: 92.0.1 (Open H264 is installed & enabled)
Desktop: KDE Plasma: 5.22.5
Video: AMD RS880 (HD4250) (Free drivers I think).

I now wonder if it was the one part of the system I didn’t consider:
The envy24-based sound card which the system has now stopped seeing. (module snd-ice1712)

Definitely the sound card, making the system use the on-board sound allows things to play again.


Might want to take a look at Envy24control - ArchWiki

It’s not a S/W problem, it’s a hardware one—lspci has stopped seeing it!

I’ve been using Envy24control since the earliest days of ALSA (before it was the default sound system), it may even have some of my code in it (certainly the driver does).