Did you follow the guide that comes with the plugin:
http://wordpress.org/extend/plugins/add-link-to-facebook/other_notes/
You need to create an APP on Facebook to give the application authorization to post to your wall.
Thread Starter
BackY
(@backy)
I already have, I gave the plugin the app’s ID and Secret bla bla..
But now the connection can’t be made..
“Press the Authorize button to allow the plugin to add links to Facebook” — did you do that step already?
If you did, than give it some time and let Facebook update it’s cache, it takes some time for your application to be properly authorized by Facebook.
Thread Starter
BackY
(@backy)
I just re-tried, after 5-6hours. does it take any more ?
