Video not loaded
The video from facebook cannot be loaded in Firefox 52 ESR while it's loaded in Chrome
https://www.facebook.com/objectivetango/videos/vb.587584967951155/1204812839561695/?type=2&theater
Disabled all addons without any luck
Vald lösning
Firefox relies on built-in OS support to play (MP4) media files via the HTML5 media player. On the Windows XP platform you do not have native support for playing MP4 files with the HTML5 media player.
You can try if the solution listed here still works for you.
Läs svaret i sitt sammanhang 👍 6Alla svar (3)
First, that video has beautiful dancing, second, please update your Firefox version to Firefox ESR as Windows XP is most compatible with that update branch. https://www.mozilla.org/en-US/firefox.../all/
(You already mentioned that you have this installed, apologies. I will leave it there for reference for a clean install if it is needed later)
Check the extensions - make sure that at lease one video player is enabled. Fix common audio and video issues
Vald lösning
Firefox relies on built-in OS support to play (MP4) media files via the HTML5 media player. On the Windows XP platform you do not have native support for playing MP4 files with the HTML5 media player.
You can try if the solution listed here still works for you.
Thanks, the solutions worked for Firefox ESR2.
Nice article in Russian that combines all needed steps at once: https://forum.mozilla-russia.org/viewtopic.php?pid=724204