I am having a problem and getting a wrong-type-argument error when trying to run org-beamer-export-to-pdf on the attached file debug.org (see backtrace below). The problem also occurs when running org-latex-export-to-pdf.

The bug can be reproduced using emacs -Q with the configuration provided in simple-config.el.

Note that the problem can be solved by commenting out the lines:
(org-babel-do-load-languages
'org-babel-load-languages
'((R . t)
(emacs-lisp . t)
(latex . t)))

yet doing this then makes it not possible to run C-c C-c on the R src block (without those lines you get an error about not being able to find ESS).

Am I just setting up org-babel incorrectly or is this a bug?

Best,
Justin

Backtrace:

Debugger entered–Lisp error: (wrong-type-argument number-or-marker-p nil)
jit-lock–run-functions(1218 1284)
jit-lock-fontify-now(1218 #<marker at 1284 in L4-6_CoDA.org<2>>)
#<subr font-lock-ensure>(1218 #<marker at 1284 in L4-6_CoDA.org<2>>)
polymode-inhibit-during-initialization(#<subr font-lock-ensure> 1218 #<marker at 1284 in L4-6_CoDA.org<2>>)
apply(polymode-inhibit-during-initialization #<subr font-lock-ensure> (1218 #<marker at 1284 in L4-6_CoDA.org<2>>))
font-lock-ensure(1218 #<marker at 1284 in L4-6_CoDA.org<2>>)
org-table-align()
org-babel-insert-result(((0.333333333333333) (0.333333333333333) (0.333333333333333)) ("value" "replace") ("R" "w1 <- c(1, 1, 1) 2 <- c(1, 1, 5) 1 <- w1/sum(…" ((:colname-names) (:rowname-names) (:result-params "value" "replace") (:result-type . value) (:results . "value replace") (:exports . "both") (:cache . "no") (:hlines . "no") (:noweb . "no") (:session . "R") (:tangle . "no")) "" nil 1072 "(ref:%s)") nil "R" (0 0 257283 648000))
org-babel-execute-src-block(nil ("R" "w1 <- c(1, 1, 1) 2 <- c(1, 1, 5) 1 <- w1/sum(…" ((:colname-names) (:rowname-names) (:result-params "replace" "value") (:result-type . value) (:results . "replace value") (:exports . "both") (:tangle . "no") (:session . "R") (:noweb . "no") (:hlines . "no") (:cache . "no")) "" nil 1072 "(ref:%s)"))
org-babel-exp-results(("R" "w1 <- c(1, 1, 1) 2 <- c(1, 1, 5) 1 <- w1/sum(…" ((:cache . "no") (:colname-names) (:exports . "both") (:hlines . "no") (:noweb . "no") (:result-params "replace" "value") (:result-type . value) (:results . "replace value") (:rowname-names) (:session . "R") (:tangle . "no")) "" nil 1072 "(ref:%s)") block nil "2da1507400b1866895fab4840062db146ee4de1e")
org-babel-exp-do-export(("R" "w1 <- c(1, 1, 1) 2 <- c(1, 1, 5) 1 <- w1/sum(…" ((:cache . "no") (:colname-names) (:exports . "both") (:hlines . "no") (:noweb . "no") (:result-params "replace" "value") (:result-type . value) (:results . "replace value") (:rowname-names) (:session . "R") (:tangle . "no")) "" nil 1072 "(ref:%s)") block "2da1507400b1866895fab4840062db146ee4de1e")
org-babel-exp-src-block((src-block (:language "R" :switches nil :parameters ":exports both :results value :session \"R\"" :begin 1072 :end 1207 :number-lines nil :preserve-indent nil :retain-labels t :use-labels t :label-fmt nil :value " w1 <- c(1, 1, 1) w2 <- c(1, 1, 5) x1 <- w…" :post-blank 1 :post-affiliated 1072 :mode planning :granularity element :cached nil :parent (section (:begin 1072 :end 1207 :contents-begin 1072 :contents-end 1206 :robust-begin 1072 :robust-end 1204 :post-blank 1 :post-affiliated 1072 :mode section :granularity element :cached nil :parent (headline (:raw-value "Spurious Conclusions" :begin 1047 :end 1285 :pre-blank 1 :contents-begin 1072 :contents-end 1284 :robust-begin 1074 :robust-end 1282 :level 2 :priority nil :tags nil :todo-keyword nil :todo-type nil :post-blank 1 :footnote-section-p nil :archivedp nil :commentedp nil :post-affiliated 1047 :title (…) :parent (org-data …) :cached t :org-element–cache-sync-key (0 . 1047))) :org-element–cache-sync-key (0 . 1071))) :org-element–cache-sync-key (0 . 1072))))
org-babel-exp-process-buffer()
org-export-as(beamer nil nil nil (:output-file "L4-6_CoDA.tex"))
org-export-to-file(beamer "L4-6_CoDA.tex" nil nil nil nil nil org-latex-compile)
org-beamer-export-to-pdf()
funcall-interactively(org-beamer-export-to-pdf)
command-execute(org-beamer-export-to-pdf)