WP4: Javascript not added to page

Hi,

I’m very new to your (very nice looking!) plugin.
I have two WordPress websites: One ith WP 3.9.2 and a commercial theme – there it works. And another one with WP 4.0 and a selfwritten theme. There the Javascript is missing on the page and though nothing is counted.
What am I doing wrong? All other plugins can add their Javascript to the page… (www.delphi-treff.de)

Thanks,
Martin

https://www.ads-software.com/plugins/wp-slimstat/