Hi John,

I've set it at follows (based on your setup) in my init.el file:

(setq org-ref-bibliography-notes "~/../Dropbox/_biblio/org-ref/bibnotes.org"
      org-ref-default-bibliography '("~/../Dropbox/_biblio/refs.bib"))

So, non-nil.

Andreas​

On 25 December 2015 at 00:45, John Kitchin <jkitchin@andrew.cmu.edu> wrote:

>
> On Thu, Dec 24, 2015 at 1:04 AM, Andreas Kiermeier <
> andreas.kiermeier@gmail.com> wrote:
>
>> org-ref-open-bibtex-notes()
>
>
> That looks like a different error that occurs in  org-ref-open-bibtex-notes().
> Up to that point everything looks normal.
>
> What do you have your org-ref-bibliography-notes variable set to? The
> default value is nil which would cause that error.
>
>
>
> John
>
> -----------------------------------
> Professor John Kitchin
> Doherty Hall A207F
> Department of Chemical Engineering
> Carnegie Mellon University
> Pittsburgh, PA 15213
> 412-268-7803
> @johnkitchin
> http://kitchingroup.cheme.cmu.edu
>
>