Facebook Login Shortcode dosen't work


I installed the Ultimate Facebook plugin on a fresh install, created fb app and configured the plugin to do Single Click Registration.

While going to mydomin/wp-login.php
and pressing on "login with facebook" everything works fine.
That means: the user is registered, logged in, and forwarded to the righ place.

I also added a shortcode on one page like this:
[wdfb_connect]Get in![/wdfb_connect]

...Here comes the tricky part...
it dosen't work :slight_frown:

The FB permission box is flashing for a moment and then nothing happens.

Whats wrong?