NOTE! This functionality is in process of being phased out.

Onyx player uses the javascript fullscreen API for going into fullscreen mode.

Older browsers do not always support this API. In those cases either the button is invisible or when clicking the fullscreen button the player will only cover the browser window and not the entire screen. This is the expected behaviour.

An overview over affected browsers can be found here: http://caniuse.com/#feat=fullscreen