Mark Forums Read?

Why does this <acronym title="e-cigarette Forum”>ECF function seem not to work? Saw comments from two years ago but nothing recent. What am I not seeing to give me more detail on how this program is to work?

Fatal error: Uncaught Exception: 12: REST API is deprecated for versions v2.1 and higher (12) thrown in /home/thevapes/public_html/wp-content/plugins/seo-facebook-comments/facebook/base_facebook.php on line 1273