As observed in https://en.wikipedia.org/wiki/1812_Overture
This happens for me in Chrome/Windows, and only if logged in (parser cache mishmash?) In console, I see:
https://en.wikipedia.org/static/1.27.0-wmf.9/extensions/TimedMediaHandler/MwEmbedModules/EmbedPlayer/resources/skins/kskin/images/ksprite.png?b0bc6 Failed to load resource: the server responded with a status of 404 (Not Found) load.php?debug=false&lang=en&modules=jquery%2Cmediawiki&only=scripts&skin=vector&version=C4Owe2Rm:89 GET https://en.wikipedia.org/static/1.27.0-wmf.9/extensions/TimedMediaHandler/MwEmbedModules/EmbedPlayer/resources/skins/kskin/images/ksprite.png?b0bc6 404 (Not Found)
Which is kinda WTF because currently deployed versions are wmf.14 and wmf.15.