Subcategorie Button doesn't appear anymore

Hello all,

its me again… I am using the liebling theme and it has the ‘more’ button and if you hover over or click on it the subcategories appear.

On my site I have the same button, in german its called ‘Mehr’ and when I hover over it the subcategories don’t appear anymore and when I click on it it directs me to a empty page, after then the subcategories appear.

Here you can se for yourself:
pw: lagava727

Any ideas on how to solve this? I also uploaded the original file, and it doesn’t work.

Please help!