Responsive HTML5 output is horribly distorted
I'm using RoboHelp 2015, trying to produce Responsive HTML. Every time I generate this output (using the Theme1_Standard layout, no customizations), this is the only thing that appears on screen:

The red bar is part of the logo on the title page. The blue border I added just to mark the edges of what I see on screen.
I am new to RoboHelp 2015. In fact, this is the first time I've used RoboHelp in more than 10 years. I have no idea what is happening. Can anyone help? I have a deadline coming up and am about to go nuts.
