Gallery not showing

The gallery added to this page is not showing. Here is what I have found:
1. The HTML is there.
2. If I add a different gallery, it works.
3. The modula-items layer shows this in the CSS
element {
position: relative;
height: 0px;
}

#3 probably explains why it’s not showing, but I did not add any inline CSS.

The page I need help with: [log in to see the link]