On Aurora, release 2.4 r861
Log in using Internet Explorer (I'm using IE11).
Make a new notebook entry or edit an old one.
Go to 'Attached Files' and click 'Upload data'
Try to drag and drop a JPB, BMP, PNG from My Pictures or elswhere on (File) Explorer.
The blue D&D box will go pink intermittently as you drag the file over the dialogue box.
But dropping the file onto the blue rectangle does nowt.
No filename appears in the list below.
Doing the same on Chrome works properly.
I haven't tried Firefox but I suspect it will work.