The text there is a little out of date, and is being revised in our
next version.
The proper setting to check is the Site URL and Base URL. You can find
these setting when you go to the Developer area of Facebook, and
Select your application -> Edit Settings -> Web Site.
From the message you show, I would recommend the following settings:
Site URL:
closenetworks.com/
Base URL: closenetworks.com
Hope this helps, and good luck,
Alex