My posts are not being linked to Facebook and at the top of my admin console Add link to facebook is giving the following error.
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.
Add link to facebook used to work fine - my App ID and Secret are correct.
I use W3Total Cache on the site - is it related to that?