End of facebook sharebutton
Facebook has withdrawn support for its famous share button. You might have noticed that either share button gone from your site or broken link at the place of share button. So its time for you to use either like or send button
From the facebook site
We deprecated the Share Button when we launched the Like button, because the Like button improves clickthrough rates by allowing users to connect with one click, and by allowing them to see which of their friends have already connected.