Error when uploading new Fontello Icon Font

Hi,
I was trying to upload a new icon font as described in your video here: http://kriesi.at/archives/enfold-version-2-3-say-hello-to-our-new-iconfont-uploader

On a first attempt it seemd to wark, but in the layout editor the new icons were just weird nonsense.
On a second attempt (after deleting the first zip file) showd this error message after uploading:

Couldn’t add the font.
The script returned the following error:
Fatal error: Call to a member function attributes() on a non-object in /homepages/1/d227302576/htdocs/f10_neu/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/font-manager.class.php on line 182

Can you help?

Thanks,
Armin