Hello

I have installed DNN 7.3.1.

When I try to use: "Insert Media" for a HTML Module, the Window opens, but then nothing works. I can't close the Tab by clicking "cancel", I can't Upload any Files/Images, and no Files are displayed. 

I also tried it with DNN 7.2.0, same Problem.

Then I tried it with DNN 7.0.0, there it's working.

Any Suggestions how to resolve this Issue?