For some reason, the Facebook button does not work but the twitter button is.
http://playaforum.info/index.php/forum-rules/introduce-yourself/#post-2
@shivors if you are using Chrome or Firefox, pressing the F12 button will open the developers console - you'll notice this
Uncaught ReferenceError: FB is not defined
at HTMLSpanElement.<anonymous> (frontend.js?ver=1.4.9:272)
at HTMLDocument.dispatch (jquery.js?ver=1.12.4:3)
at HTMLDocument.r.handle (jquery.js?ver=1.12.4:3)
Are you using any minification plugins ? If so, you probably want to exclude wpForo and any essential JS files that have dependencies such as this.
The FB App is not configured correctly. Please delete the App and create/configure new one. Also please make sure FB SDK is enabled.
Also please disable other plugins, delete all caches, disable optimization and CSS/JS minification functions and test it again.