Youtube videos not appearing at all

Hi

I have read multiple bits of advice for embedding youtube videos into a storyline file and followed them all without success. I have tried simply embedding the video and I have tried embedding it as a web object. The original worked in the preview but not the published file. The web object kind of worked in the preview (I could see the object but it stated that it would not play.) but in the actual slide. It came up blank in every case. Just wondering if there is a setting I have wrong as I can not even get the video to appear.  I have attempted to to do this in both Firefox and Chrome with no success.

Any advice would be really appreciated.

Thanks

Ashleigh