Facebook has modified and updated their API today which has affected the ability of allArticleAnnounce to post to Facebook. We have immediately made the required changes to the extension which resolves this issue.
The fix has only been applied to the latest version of allArticleAnnounce, which can be accessed through your account subscription menu once logged in. If you are in possession of the most recent version, the only file which will require replacing is allArticleAnnounce- (Contents).zip
If you do not have the latest version, please upgrade by uninstalling the older version (1.0.0 and 1.0.2) and then installing the latest version (1.1.0).