When using Firefox 52.0.2 (64bit) it gets impossible to scroll in the administration backend.
Steps to reproduce:
- create or edit a content with a ezrichtext field
- click to Create a new content to embed into the ezrichtext field
- choose the default "Article" content type
- choose a location
- the page with the New "Article" form is displayed
- scrolling on the form will be impossible
If the content type has many fields it will not be possible to reach them, because there's to way to scroll down.