I have the black images problem too, on multiple machines and ONLY in Safari. It only happens when you right click an image and choose "Save image to Evernote". I had this problem for at least the last few months using latest versions of everything. I just changed computers (this week) to a brand new 2015 Mac Book Pro. Installed EN from App store (v6.0.6). Installed web clipper from EN website (v6.2.4). I'm still having the same problem. Installed web clipper on chrome on the new machine and it works fine. It appears you have a bug in the Safari version of the clipper.