Hey it seems there's a problem to display the smiley-button and/or the actual window.
I'm using a slightly customized twentythirteen theme, bbpress and another plugin to enable the full TinyMCE inside the front end (bbpress).
Any idea what the problem can be caused through? Inside the backend it works.
The website is http://hundesozialstrukturen.de/forum/ and you need to login to see the editor: