Trying to import video into animate

Hi,

Im using the trial version and trying to import a video into the tutorial file > Using HTML5 components

> https://helpx.adobe.com/animate/how-to/using-html5-components.html?playlist=/services/playlist.helpx/products:SG_ANIMATE/learn-path:key-techniques/playlist:topic/set-header:design-accessible-content/en_us.json&ref=helpx.adobe.com

When I click browse on the component parameteres and select the video, when I come to test it in browser the video does not play. Also if I go to file > import, then the "import video" option is greyed out?

The video file is a small mp4 file.

Thanks

Baz