Thanks Kyle, I deleted both packages, but the problem still persists. I am using the latest version of org and help-bibtex-2.0.0 that I just pulled from Melpa. I also pulled the latest version org-ref Strange but I will keep digging Cheers, M > On Feb 23, 2021, at 5:53 PM, Kyle Meyer wrote: > > Marvin M. Doyley writes: > >> Hi there, >> >> For some reason org-ref-helm-insert-cite-link is not working anymore >> for me. When I try to execute it, I get the following error >> helm-bibtex-candidates-formatter: Symbol’s function definition is >> void: bibtex-completion-candidates-formatter > > I don't use org-ref or helm-bibtex, but, based on poking around in their > repos, helm-bibtex removed bibtex-completion-candidates-formatter way > back in 390e9c3 (move helm-specific code to helm-bibtex.el, 2016-09-27), > which in turn led to 400c4f4 (use helm-bibtex-candidates-formatter, > 2016-10-01) on org-ref's side. So... > >> Does anybody know how to fix this? > > ... while it's not really a satisfying answer, I suspect your issue will > be fixed by uninstalling both packages, including the *.elc files, and > reinstalling.