Now that the App Profile Page is no longer available, I tried using this link provided by Facebook to open a specific file on a WordPress website to the custom tab:
http://www.facebook.com/dialog/pagetab?app_id=YOUR_APP_ID&redirect_uri=YOUR_URL
This worked well for yoururl.com/
(main directory) which is also the index.php
home page of the website. However, when I attempted to use a custom tab to connect to a different page on the site, such as yoururl.com/about/
I received the dreaded 191 error message:
API Error Code: 191
API Error Description: The specified URL is not owned by the application
Error Message: redirect_uri is not owned by the application.
The workaround I ended up using was to copy the source code of the page by hand and create a new standalone HTML document, but I would really rather have the custom tab open the actual page so my client can update the WordPress herself without me having to edit the HTML for small changes.
Any advice?