Add Link to Facebook – : Get me: Error validating access token: Session does not match current stored session.
This may be because the user changed the password since the time the session was created or Facebook has changed the session for security reasons.
If you’re using your own Access Token then the easiest way to check whether it works is to test it on the Demo page.
Simply check the option which says ‘Test my Access Token’ and paste it in to see whether or not it’s valid.
Solution: Try creating a new post on your page or in your group and then viewing the plugin’s feed again.