MediaWiki:Mwe-embedplayer-fullscreen-tip/en
This message is missing 'to' (and 'the'?):
- Press <b>F11</b> to toggle the <i>web browser</i> fullscreen
— Mar(c).
I have submitted a patch for this here: https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/TimedMediaHandler/+/483067/