I have had this error message when I tried to set this up on a site I had a few months ago and could not get round it, tried reinstalling everything, re-entering the app id, secret, page id etc. and also the FB settings for the app.
Tried again today.....Even though in WP it says click grant access and authorise the plugin to post to your page, it doesn't say this when I click grant access, it says
My App would like to access your public profile, friend list and groups.
If I click cancel OR ok it goes to a page in FB and says:
You are using Facebook as My-Page-Name
To access this page, you'll need to switch from using Facebook as your page to using Facebook as yourself.
If I click to use FB as my own name - which is my main account it just goes the My-Page-Name FB site and that's it, no notification of what I need to do next if anything. So I go back to my WP site and go round the loop again, same thing. This is error message in WP that remains no matter what I do:
Some or all access permissions are missing. Please click the button Grant access rights! and authorize the plugin to post to your Facebook profile or page.
[Error occurred at line 778]
Your page or profile's access permissions could not be verified.
So any ideas what to do?
P.S. I have latest version of facebook publish 2 installed as well