org-bibtex-yank failing with error Wrong type argument: stringp, nil

[J. G.]

Hi, I'm trying to figure out why I'm getting consistent failures using 
org-bibtex-yank. This appears to be identical to the problem posted here:

https://stackoverflow.com/questions/31174281/org-bibtex-yank-fails-with-wrong-type-argument-stringp-nil

On my system I am using a fresh Ubuntu 23.04 VM with the following emacs and 
org-mode build info:

GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.37, cairo 
version 1.16.0) of 2023-08-11

Org mode version 9.7-pre (release_9.6.7-652-gcfea24 @ /home/test/org-mode/lisp/)

My backtrace is very similar to that posted in the stackoverflow thread:

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  looking-at(nil)
  bibtex-parse-entry()
  org-bibtex-read()
  org-bibtex-yank()
  funcall-interactively(org-bibtex-yank)
  call-interactively(org-bibtex-yank record nil)
  command-execute(org-bibtex-yank record)
  execute-extended-command(nil "org-bibtex-yank" nil)
  funcall-interactively(execute-extended-command nil "org-bibtex-yank" nil)
  call-interactively(execute-extended-command nil nil)
  command-execute(execute-extended-command)

My steps to reproduce, with this as my init.el file:

(add-to-list 'load-path "~/org-mode/lisp")
(require 'org-loaddefs)

1. Open test.org in emacs.

2. Copy a bibtex entry in Firefox, for example this entry from Google Scholar:

@article{dominik2004org,
  title={Org Mode Manual},
  author={Dominik, Carsten},
  year={2004}
}

3. In the org file call M-x org-bibtex-yank.

After that I experience the failure above 100% of the time.

Attempts to troubleshoot:

One of the comments in the stackoverflow thread mentioned that a reason this 
could have failed was that the variable "bibtex-dialect" wasn't set. C-h v 
confirms it was set in my case (to "BibTeX"), but the problem was still 
present. I added a line in my init.el file "(setq bibtex-dialect 'biblatex)" 
just to double check and the problem was still present.

As described in the same comment, with my original 2 line init.el file above,

1. simply opening a new file "dummy.bib" (doing nothing with it),

2. then opening "test.org",

3. copying a bibtex entry in Firefox,

4. calling org-bibtex-yank

caused org-bibtex-yank to correctly function. I did not need to call 
bibtex-set-dialect as the comment described.