Firefox and Twitter videos

When I try watching a Twitter video in “firefox”, I get:

  • The media could not be played

This worked with “firefox” only a few days ago. And the same video plays in “chromium”. I’m not sure what changed.

No, it was not the recent “firefox” update. I only installed that yesterday evening, but the problem was showing up earlier in the day. Also, it is not a firefox extension. I tried with an alternative firefox profile where there are no extensions, and I see the same problem.

I bumped into an answer: Embedded Twitter videos won’t play