Sorry, I am missing something.

On the homepage I created a new HTML Area.  Inside that I added a <video> tag with a MP4 and WEBM source.  For some reason, the header image I had is still there (even though I deleted the area from the page) and the video section is not getting loaded at all.  When I inspect the page, the <video> tag does not show up at all.  Is there anything preventing it from loading?  Tried clearing the cache, but that didnt help. Also tried other browsers with no better luck.

As a related but separate issue, when I try to add a video it says that the URL is invalid. I have tried the full version of the youtube URL, and several variations, but none of them work.  Is there a specific URL structure it is looking for?  I get this same error whether I try to upload a video in (FILES -> Add Video) or if I add a Video Reference area to  the homepage.   I ended up FTPing the video files directly onto the server.

This is the URL for reference:  https://www.youtube.com/watch?v=DtMbHRi9DSY

Thanks