I've checked this a little further -- the current org mode on ELPA does
not fail in the same way -- org-map-entries has changed the call from:
(org-agenda-prepare-buffers
(list (buffer-file-name (current-buffer))))
to:
(org-agenda-prepare-buffers
(and buffer-file-name (list buffer-file-name)))
which fixes the problem.
Is org-mode in core going to be updated before 25.1?
--
Kaushal Modi