I created all the base pages I need to be able to set up my nav correctly, all of which have a "default" template page chosen. When I use the front end of the site, I can see that there's content there -- for instance, on the contact page, there's a background image, contact form widget, and some text.
As soon as I go to the page and select "upfront", I get what you see in the attached screenshot. There's nothing visible to edit, and I can't drag new elements in. The page is completely static. I've tried logging out, clearing my cache, reloading the pages, etc. but it doesn't seem to be working.