I love the Dynamic Content Gallery but it was making me nuts. I am not a code-knowledgeable person and I found their documentation not thorough enough. However - success has been achieved!
If the black box does not appear - make sure your Front Page is not checked off for Static!
If the black box does appear, but no images show up - it could be a conflict with another plugin. My issue was Events Manager Extended. The developer there figured it out - here's his answer:
Now my site (http://www.menopauseinmanhattan.com) is working great!