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Videos won't play and plugins may not be working

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I am no longer able to play videos on Twitter, Facebook or other sites such as the UK's channel 4 on demand streaming service and BBC iPlayer.

On twitter I get the same error described on this page: https://forums.guru3d.com/threads/firefox-will-not-play-videos-on-twitter.419952/ . See image 1 for the Browser Console log.

On Facebook, if I click a video I just get a black video with the video duration shown as 0:00 (as thought the video has not loaded).

On the UK's channel 4 service I get an error message saying, "Digital Rights Management (DRM) Not Enabled. You must enable DRM in Firefox to play video on channel4.com. Click the "Enable DRM" button provided above". However the Widevine plugin is present on Firefox and is set to "always activate". See image 2 for the Browser Console log.

On BBC iPlayer, I get an error message saying, "The content doesn't seem to be working. Please try again later". See image 3 for the Browser Console log.

When I go to https://www.youtube.com/html5 "H.264" and "MSE & H.264" are shown as red exclamation marks.

I have tried the solutions mentioned on the web (such as clearing cache, turning off content blocking, clearing cookies & site data, creating new profile, refreshing Firefox, uninstalling Firefox (including from the registry) and reinstalling, etc) and nothing has worked. These issues are not resolved by opening Firefox in Safe Mode.

Any assistance would be greatly appreciated. Thank you!

I am no longer able to play videos on Twitter, Facebook or other sites such as the UK's channel 4 on demand streaming service and BBC iPlayer. On twitter I get the same error described on this page: https://forums.guru3d.com/threads/firefox-will-not-play-videos-on-twitter.419952/ . See image 1 for the Browser Console log. On Facebook, if I click a video I just get a black video with the video duration shown as 0:00 (as thought the video has not loaded). On the UK's channel 4 service I get an error message saying, "Digital Rights Management (DRM) Not Enabled. You must enable DRM in Firefox to play video on channel4.com. Click the "Enable DRM" button provided above". However the Widevine plugin is present on Firefox and is set to "always activate". See image 2 for the Browser Console log. On BBC iPlayer, I get an error message saying, "The content doesn't seem to be working. Please try again later". See image 3 for the Browser Console log. When I go to https://www.youtube.com/html5 "H.264" and "MSE & H.264" are shown as red exclamation marks. I have tried the solutions mentioned on the web (such as clearing cache, turning off content blocking, clearing cookies & site data, creating new profile, refreshing Firefox, uninstalling Firefox (including from the registry) and reinstalling, etc) and nothing has worked. These issues are not resolved by opening Firefox in Safe Mode. Any assistance would be greatly appreciated. Thank you!
Attached screenshots

All Replies (3)

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If you are having issues with the H.264 codec, you need to reinstall the Windows Feature Pack.

This is the software that Firefox uses to play that format of video. It's fairly common for something like a Windows update to damage that, so reinstalling it usually helps to repair it.

Hope this helps.

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Thanks for your reply.

I am running Windows 10 Home (not K or KN) so Windows Feature Pack is already installed. I tried to toggle it off/on via Windows Features in the Control Panel but unfortunately this resulted in my registry somehow becoming corrupted and I had to do a fresh Windows install. In any case Firefox is working fine now!

Thanks for your assistance in any case.

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Well, glad that you managed to fix it!