I've used Clipper a lot in the past for research, but now mine has stopped working too. It has been a bit iffy for a while now, but stopped working completely and I have the feeling it was when Safari last updated. Prior to that I had to highlight the bit I wanted to clip, then right click and choose "save highlight to Evernote". Now I right click, choose "save highlight to Evernote" and ... absolutely nothing. No drop down box and no clip saved. Zilch. I'm on Yosemite still (that's another story).