Appointments + plugin not working

Problem with the Appointments + plugin. I have it installed, I set the work hours and added the shortcode to a page. I get the calendar and the times to select, but when you click on a free time, nothing happens. I looked at the FAQ and it says go to Google Chrome or Firefox and then press Ctrl+Shift+j. In the opening window if you see any warnings... No warnings. I have deactivated all my plugins, to see if there's a conflict, and it still does nothing.
Any thoughts?