We recently upgraded to 3.4.1 from some ancient version of Mockups. When I try and edit from inside Firefox, I get a white screen and the editor never loads.
A message is briefly flashed saying “Flashplayer 10 or higher is required”, but it then navigates to what is supposed to be the edit page and shows a featureless blank screen. I checked and confirmed that I had the latest version of Flash installed.
Editing the same page from Chrome works fine.
Our Confluence instance is hosted by Atlassian.