Lightbox issue

I created a link to a lightbox screen on the Slide Master screen.  The light box consist of buttons that link to screens throughout the course, a Main Menu.  The lightbox screen is in it own Scene btw.

Everything works fine on my PC, but when I export it (HTML5 only) and access it via iPad there are problems.  The light box window opens and when I click one of the buttons everything disappears except for the 'x close' button and the frame of the lightbox window.  Also, the course freezes at this point. 

Anyone know what's going on here and how to possibly resolve it?

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