Hi I was able to repair the problem by setting the temp buffer that is created within ort-html-format-latex to org-mode. I put the function with the added line marked by PATCH here: #+BEGIN_SRC elisp (defun org-html-format-latex (latex-frag processing-type info) "Format a LaTeX fragment LATEX-FRAG into HTML. PROCESSING-TYPE designates the tool used for conversion. It is a symbol among `mathjax', `dvipng', `imagemagick', `verbatim' nil and t. See `org-html-with-latex' for more information. INFO is a plist containing export properties." (let ((cache-relpath "") (cache-dir "")) (unless (eq processing-type 'mathjax) (let ((bfn (or (buffer-file-name) (make-temp-name (expand-file-name "latex" temporary-file-directory)))) (latex-header (let ((header (plist-get info :latex-header))) (and header (concat (mapconcat (lambda (line) (concat "#+LATEX_HEADER: " line)) (org-split-string header "\n") "\n") "\n"))))) (setq cache-relpath (concat "ltxpng/" (file-name-sans-extension (file-name-nondirectory bfn))) cache-dir (file-name-directory bfn)) ;; Re-create LaTeX environment from original buffer in ;; temporary buffer so that dvipng/imagemagick can properly ;; turn the fragment into an image. (setq latex-frag (concat latex-header latex-frag)))) (with-temp-buffer (insert latex-frag) (org-mode) ; <--- PATCH (org-format-latex cache-relpath cache-dir nil "Creating LaTeX Image..." nil processing-type) (buffer-string)))) #+END_SRC Best regards, Derek On Sun, Jan 24, 2016 at 11:24 AM, Derek Feichtinger wrote: > Dear Org maintainers > > HTML export of equations leads to an error since my last update from > MELPA, yesterday. I can trace it back to the invocation of > org-element-context in a temporary buffer in fundamental mode. A more > exact analysis follows. > > Emacs : GNU Emacs 24.5.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.8) > of 2015-05-04 on dflt1w > Package: Org-mode version 8.3.3 (8.3.3-17-gce80a0-elpaplus @ > /home/dfeich/.emacs.d/elpa/org-plus-contrib-20160118/) > > > The error can be reproduced using a minimal org file with these contents: > > #+BEGIN_EXAMPLE > * Equation export error > > This equation produces an error on html export > > $$ > U = R \cdot I > $$ > > #+END_EXAMPLE > > Upon export to html the following error and backtrace result (I took > the liberty of cutting the lines to avoid special characters). > > #+BEGIN_EXAMPLE > Debugger entered--Lisp error: (wrong-type-argument stringp nil) > looking-at(nil) > byte-code("\212\214~\210... > org-element-context() > org-format-latex("" "" nil "Creating LaTeX Image..." nil mathjax) > org-html-format-latex("$$\n ... > org-html-latex-fragment((latex-fragment ... > org-export-data((latex-fragment ... > #[(element)... > mapconcat(#[(element)... > org-export-data((paragraph... > #[(element) "\302... > mapconcat(#[(element)... > org-export-data((section... > #[(element) "\302... > mapconcat(#[(element)... > org-export-data((headline... > #[(element) "\302... > mapconcat(#[(element) "\302... > org-export-data((org-data nil (headline (:raw-value "Equation export > error" :begin 1 :end 108 :pre-blank 1 :contents-begin 26 :contents-end 104 > :level 1 :priority nil :tags nil :todo-keyword nil :todo-type nil > :post-blank 2 :footnote-section-p nil :archivedp nil :commentedp nil > :post-affiliated 1 :title (#("Equation export error" 0 21 (:parent #1))) > :parent #0) (section (:begin 26 :end 108 :contents-begin 26 :contents-end > 104 :post-blank 2 :post-affiliated 26 :parent #1) (paragraph (:begin 26 > :end 76 :contents-begin 26 :contents-end 75 :post-blank 1 :post-affiliated > 26 :parent #2) #("This equation produces an error on html export\n" 0 47 > (:parent #3))) (paragraph (:begin 76 :end 104 :contents-begin 76 > :contents-end 104 :post-blank 0 :post-affiliated 76 :parent #2) "" > (latex-fragment (:value "$$\n U = R \\cdot I\n $$" :begin 78 :end 103 > :post-blank 0 :parent #3)) #("\n" 0 1 (:parent #3)))))) (:export-options > nil :input-buffer "err-example.org" :input-file "/tmp/html-exp-error/ > err-example.org" :html-doctype "xhtml-strict" :html-container "div" > :description nil :keywords nil :html-html5-fancy nil :html-link-use-abs-url > nil :html-link-home "" :html-link-up "" :html-mathjax "" :html-postamble > auto :html-preamble t :html-head "" :html-head-extra "" :subtitle nil > :html-head-include-default-style t :html-head-include-scripts t > :html-allow-name-attribute-in-anchors nil :html-divs ((preamble "div" > "preamble") (content "div" "content") (postamble "div" "postamble")) > :html-checkbox-type ascii :html-extension "html" :html-footnote-format > "%s" :html-footnote-separator ", " ...)) > org-export-as(html nil nil nil (:output-file "./err-example.html")) > org-export-to-file(html "./err-example.html" nil nil nil nil nil) > org-html-export-to-html(nil nil nil nil) > org-export-dispatch(nil) > call-interactively(org-export-dispatch nil nil) > command-execute(org-export-dispatch) > #+END_EXAMPLE > > From the debugger I can see that the org-element-context is executed in a > temporary buffer: > > : Debugger Eval ((point)): 1 > : Debugger Eval (major-mode): fundamental-mode > : Debugger Eval ((buffer-name)): *temp*-831342 > : Debugger Eval ((buffer-string)): $$ > : U = R \cdot I > : $$ > > > I can reproduce the error by creating a file and filling it with the > contents > that "buffer-string" yielded and opening it in fundamental mode. > #+BEGIN_EXAMPLE > $$ > U = R \cdot I > $$ > #+END_EXAMPLE > > When I now execute "org-element-context" with point at 1 then I get the > same error: > > Debugger entered--Lisp error: (wrong-type-argument stringp nil) > looking-at(nil) > byte-code("\212\214~\210... > org-element-context() > eval((org-element-context) nil) > eval-expression((org-element-context) nil) > call-interactively(eval-expression nil nil) > command-execute(eval-expression) > > If the buffer is set to org-mode, the error does not appear, and > org-element-context > correctly recognizes the text as a latex-fragment. > > > Best regards, > Derek > >