@Sakin: thanks again for trying to help!
I did exactly as you told me… but with no result.
I put this in the Webmaster Tools => Code to display on Header
<div id=”fb-root”></div>
<script>(function(d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) return;
js = d.createElement(s); js.id = id;
js.src = “//connect.facebook.net/de_DE/sdk.js#xfbml=1&version=v2.0″;
fjs.parentNode.insertBefore(js, fjs);
}(document, ‘script’, ‘facebook-jssdk’));</script>
Then I put this in Appearance => Widgets => Catch Everest Socisl Widget => Main Sidebar => Text:
<div class=”fb-like” data-href=”http://kunstkursekuehne.de/” data-width=”450″ data-layout=”standard” data-action=”like” data-show-faces=”true” data-share=”true”></div>
But the homepage looks all the same http://kunstkursekuehne.de/
And the same result I get with the IFrame Code in Appearance => Widgets
<iframe src=”//www.facebook.com/plugins/like.php?href=http%3A%2F%2Fkunstkursekuehne.de%2F&width=450&layout=standard&action=like&show_faces=true&share=true&height=80″ scrolling=”no” frameborder=”0″ style=”border:none; overflow:hidden; width:450px; height:80px;” allowTransparency=”true”></iframe>
What I do wrong? Please!