How to enable firefox to support H.264 and MSE & WebM VP9 on Windows Server 2008 R2 that is affecting your YouTube video playback.

I have been having intermittent issues with video playback on sites like Facebook and YouTube. Videos would either play without sound or they will not be able to load when clicked. Embedded video on some website site also suffers the same issue once in a while.

I used to be able to live with this issue as I only encounter them once in a while. But recently, there are more and more videos that will not play on my firefox browser. Finally, I have had enough of the nonsense and decide to fix the problem once and for all.

This is one of the issues with the YouTube videos on my firefox browser. The video just will not play.

You can go to this link on your firefox browser to test your HTML5 supportability https://www.youtube.com/html5

As you can see from my screen shot, there’s an issue with the H.264 and MSE & WebM VP9 on my Firefox browser.

This is the version of my firefox browser at the time I am debugging this.

After lots of research, testing, tweaking and fault finding (on and off the internet), I have finally solved the issue. From what I understand (from all the research), the Firefox browser does not come with its own H264 decoder. It relies solely on the OS to provide the decoder in order decode H264 videos. For my case, the default Windows Server 2008 Desktop experience installation did not contain a H264 decoder. To solve the problem, all you need to do is to download a patch (KB2483177) from Microsoft, install that and you are done.

Link to download the patch: https://support.microsoft.com/en-us/help/2483177/fix-you-cannot-play-back-an-h-264-video-file-or-an-aac-audio-file-on-a