At the time of writing, our popular Joomla! extensions allArticleAnnounce and allInstantFacebook are not publishing to business and community pages.
What we know about the problem:
it's a new bug, introduced by an update detailed in a Facebook blog post late last month, which 'should not break any applications'. Facebook's own publishing test console doesn't work anymore. Type a message and click Call Method, and the error comes up. The problem is listed on the Facebook bug tracker, and allArticleAnnounce apparently isn't the only application affected.
Note this this problem is only affecting business pages in Facebook - publishing to your personal facebook page is still functional. Our developers are working on a fix or workaround, and we will update you as soon as we can.