Hi
I have been having the same issue. When i click on the insert/upload image button, i get a blank page that just says “Add media files from your computer” with no other options.
I can how ever click on the URL and the Media library tabs and they seem to work fine.
I have tried all the steps mentioned about but nothing seems to work.
I am using the latest version of wordpress. I have tried it in safari, firefox and google chrome. With the same result.