Hi John,
Its now working, it turns out the version of pdftotext that I was using wasn’t working well. I found different version (http://macappstore.org/pdftotext/) that did the trick

cheers,
M

On Dec 23, 2015, at 4:30 PM, John Kitchin <jkitchin@andrew.cmu.edu> wrote:

Thanks! Do you know if you have pdftotext working on your machine? The pdf drag-n-drop works by converting the pdf to text, and than matching a pattern to find a doi. If none is found, you get the message you noted. The url dnd works similarly, but there are a bunch of recipes for what to match depending on the base of the url.

I did that on a Mac, and I haven't tested it on a windows or Linux machine. 

John

-----------------------------------
Professor John Kitchin 
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803

On Wed, Dec 23, 2015 at 4:22 PM, marvin doyley <marvinpas@gmail.com> wrote:
Hi John,

I am playing with org-ref,  the melpa version.

Everything works fine except, one thing.  When I drag a pdf to an empty bibtex file it doesn’t extract the doi ( no doi found in the file:///). I tried it pdf you used  in your video (Examples of Effective Data Sharing in Scientific Publishing), but I got the same error. Dragging the url to the bibtex file also doesn’t works for me.

cheers,
M

PS by the way, your video was excellent :)