This is really annoying. Yesterday everything was working fine, now I wake up only to realize that all the videos on YouTube are using the HTML5 player.

Here is what I see when I try to play a video on YouTube: enter image description here

I tried what was suggested by the accepted answer in this question, but it didn't work, even after restarting Firefox.

Also I would like to note that YouTube works fine in Chrome (HTML5 player) and Internet Explorer (flash player).

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3 Answers

Check if the latest version of Flash is properly installed on your browser. If not, download the latest version and install it.

Then, install the YouTube Flash Player extension:

This add-on forces YouTube to play videos using Flash Player instead of the HTML5 player.

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You can force YouTube to play a video with flash player by adding &nohtml5=1 or &nohtml5=True to the URL.

Found this after I had uploaded a video to YouTube and there was "&nohtml5=False" automatically added by any reason.

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Firefox has release MSE support for HTML5 playback. This uses the system hardware decoders unless the driver is blacklisted. Setting media.windows-media-foundation.use-dxva=false in about:config will use software decoding.

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