After installing CC 2015 and installing the 'Animated Thumbnail Gallery' extension using the DMX installer, it seemed all should work fine. The button appears in the 'insert' tab.So I clicked it to insert a gallery.
The pop-up window opens, and a view seconds later the little message at the top right corner with a hint to use control-click.
But thats about it that works.
When I move the mouse to the 'add image folder' to highlights, but when I click it nothing happens. Also the 'add image' doesn't work.
The only hing I can do is close the pop-up window again.

I reinstalled the extension and disabled all the others I use, but nothing matters. I can not click anything in the pop-up window.
I also noticed that the little hint in the top right corner should show an image, but this gives a question mark, like the images is not found.

Any hints to solve this?

Cheers