“Additional options” button not working

Hi,

I was looking for a product filter for my webshop and found this one. Before i buy it, i would first try it. But a few minutes after installion i had my first problem. The problem as descriped in the topic title. I allready found another topic with this problem. And the answer was that it is a js error. I use chrome and searched for a js error. But found nothing. I hope you can help me.

Kind regards, Martijn