Testimonials and Editor Widget do not work in Sydney theme

Hi,
everything works fine until I actually add the Testimonial or Editor widget to a page/post (within or outside another widget). After I click edit, I can use all features fine but when I want to click “done”, nothing happens. Same with all other “frame buttons” (i.e. close, arrows). To get out of this I have to reload the page.
We use the sydney theme. You can find our store here: www.eshop-guide.de
Thanks for your support
Patrick

URL: http://www.eshop-guide.de