In addition, Chrome works perfectly. I have this issue only on Firefox.

Is this with the Shockwave Flash player or with the HTML5 media player?

You can check this via the right-click context menu of the player area. A Flash based player shows a context menu with the Flash version.

many have the same problem

cor-el said

Is this with the Shockwave Flash player or with the HTML5 media player? You can check this via the right-click context menu of the player area. A Flash based player shows a context menu with the Flash version.

I have uninstalled/reinstalled adobe flash player, and the issue persists. In my opinion, it's a Firefox bug.

I think it's HTML5, since when I rightclick any facebook video, a little window with 3 option appears (it has nothing to do with flash video menu).

I have the same problems.

Some of the videos play with sounds, but most of them do not.

I check the plugins, add ons, many things but still no work.

Other browsers (including Edge) still play them good. So I think the problems are dued to Firefox

How can we report the issue to Firefox?

It seems the issue is gone.