Forum Facebook like button error
 

I'm getting a red Error on my pages, and when clicked it says The href URL must be absolute

I'm running 4.1.2 and searched for a solution and thought I'd found one, but I couldn't add the plugin per the instructions by Joe D. because I don't have the required fb_like_button hook. I also tried the edit of the /includes/functions_facebook.php file but my file is different and I couldn't find the lines to edit.

Can someone point me in the direction to fixing this problem?

Thanks!