Hot answers tagged html5
Right-click the video when it is playing or not and the context menu that pops up will tell you if you are using Adobe Flash Player or the YouTube HTML5 Video Player. This is the right-click menu for the two cases: In Firefox 36: Google Chrome 41.0: You can find out if you are using YouTube HTML5 Video Player as the default player for playing ...
It is most likely an issue specific to your graphics card. Please file a bug at https://bugzilla.mozilla.org/enter_bug.cgi?product=Core then choose the video/audio component. Paste in the information from about:support and the right people will get notified and will jump onto it immediately.
Here is an extension that forces Flash on YouTube (tested on 02/05/2015). Also, to remove the annoying fullscreen message type in the address bar: chrome://plugins/, find: "Adobe Flash Player" and check the box next to Always allowed.
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