Has your facebook LIKE button suddenly disappeared from your website, even though you didn’t make any code changes?

It surely disappeared on my page over night and after a quick look at the javascript error log, I found this error in the http://connect.facebook.net/en_US/all.js script: e.root is undefined

After a bit of googling I found a solution:

just before the div that contains the facebook javascript add another div with the id “fb-root” like so:

<div id=”fb-root”></div>
 <div class=”facebook-button” >
 <script src=”http://connect.facebook.net/en_US/all.js#xfbml=1″></script>
 <fb:like show_faces=”false” width=”200″ font=””></fb:like>

and … working again !