Found it my self.
Remove in the templates the normal <?php wp_footer() ?>. This will load your normal footer but this template is noh loading your normal header and thus missing important files.
And in google_fonts.php line 19 change http:// to https://.
Laden van gemengde actieve inhoud ‘http://fonts.googleapis.com/css?family=Kreon%3A300%2C400%2C700’ geblokkeerd
ReferenceError: jQuery is not defined
