Hello,
I updated the YouTube URL for the intro video on the GK University template. I did not change any other code, but the box disappeared. This is currently what is in the field.
<p><a href="https://www.youtube.com/embed/ndRux_c7fkQ" rel="{handler: 'iframe', size: {x: 640, y: 480}}" class="modal gkVideoBlock">Take a tour</a></p>