In reply to Chris Aldrich.

At some point I’ll install the Twenty Fifteen theme and try to figure it out. I believe it has something to do with the post loop and how that is coded. The form looks for the post loop. In fact, I noticed that the blog must have at least one post or the form will not show up. That’s something I may be able to fix in the future. But for now if anyone installs this on a brand new blog with zero posts, they have to do one post first from the backend, then they’re good to go. Of course, fresh WordPress installs come with one sample post already and so it may be somewhat rare for someone to experience this phenomenon.