When you Drag & Drop a file from your OS into the Header Element of the etherpad (see gif),it accepts the file and lets the browser open it / Or try to download it, which breaks everything for the user. Can this somehow be prevented? It happens on Linux & Windows with FF and Chrome (Haven't tested anything else) with your demo, the sandstorm demo and the primarypad demo as well.
Dropping into the text is just getting ignored by etherpad (That is the behaviour that we would expect from the header aswell)

When you Drag & Drop a file from your OS into the Header Element of the etherpad (see gif),it accepts the file and lets the browser open it / Or try to download it, which breaks everything for the user. Can this somehow be prevented? It happens on Linux & Windows with FF and Chrome (Haven't tested anything else) with your demo, the sandstorm demo and the primarypad demo as well.
Dropping into the text is just getting ignored by etherpad (That is the behaviour that we would expect from the header aswell)