Hi Thomas,
Don’t know if this will help:
Remembered that I changed from Internet Explorer to Microsoft Edge because issues around WWMC’s videos. Making a test with Internet Explorer today, resulted in a black box where a WWMC “dearly missed introduction” should have been displayed; but clicking on the <button>/alternative saying “alternative player” resulted in the introduction image coming back.
Sven-Olof Jansson
London, UK; Boston, MA