Remember to cover the basics, that is, what you expected to happen and what in fact did happen. You don't know how to make a good report? See
https://orgmode.org/manual/Feedback.html#Feedback Your bug report will be posted to the Org mailing list. ------------------------------------------------------------------------ Hello org-mode team, I encountered the following error while opening an org buffer: Error during redisplay: (jit-lock-function 1) signaled (wrong-type-argument number-or-marker-p nil) Here's the minimum reproducable content of the buffer: #+BEGIN_SRC markdown #+END_SRC (that is, just an empty markdown source block). I have markdown-mode https://jblevins.org/projects/markdown-mode/ installed. After some debugging, I've found that the error happened in `font-lock-fontify-keywords-region` function. It calls `org-fontify-meta-lines-and-blocks` and got `t` as the result, but the matching data is not set. The following advice can fix the bug for me: (defun my/fix-org-fontify-meta-lines-and-blocks (res) (when (and res (null (match-beginning 0))) (set-match-data (list 0 0))) res) (advice-add 'org-fontify-meta-lines-and-blocks :filter-return #'my/fix-org-fontify-meta-lines-and-blocks) Emacs : GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.30, cairo version 1.17.4) of 2021-09-15 Package: Org mode version 9.4.4 (release_9.4.4 @ /usr/share/emacs/28.0.50/lisp/org/) current state: ============== (setq org-link-elisp-confirm-function 'yes-or-no-p org-directory "~/Notes" org-bibtex-headline-format-function #[257 "\300\236A\207" [:title] 3 "\n\n(fn ENTRY)"] org-agenda-files '("~/Notes/gtd/") org-export-before-parsing-hook '(org-attach-expand-links) org-refile-use-outline-path t org-archive-hook '(org-attach-archive-delete-maybe) org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-hide-drawers org-cycle-show-empty-lines org-optimize-window-after-visibility-change) org-mode-hook '(#[0 "\301\211\207" [imenu-create-index-function org-imenu-get-tree] 2] #[0 "\300\301\302\303\304$\207" [add-hook change-major-mode-hook org-show-all append local] 5] #[0 "\300\301\302\303\304$\207" [add-hook change-major-mode-hook org-babel-show-result-all append local] 5] org-babel-result-hide-spec org-babel-hide-all-hashes) org-confirm-shell-link-function 'yes-or-no-p outline-isearch-open-invisible-function 'outline-isearch-open-invisible org-agenda-before-write-hook '(org-agenda-add-entry-text) org-src-mode-hook '(org-src-babel-configure-edit-buffer org-src-mode-configure-edit-buffer) org-confirm-elisp-link-function 'yes-or-no-p org-clock-out-hook '(org-clock-remove-empty-clock-drawer) org-speed-command-hook '(org-speed-command-activate org-babel-speed-command-activate) org-tab-first-hook '(org-babel-hide-result-toggle-maybe org-babel-header-arg-expand) org-link-shell-confirm-function 'yes-or-no-p org-babel-pre-tangle-hook '(save-buffer) org-agenda-loop-over-headlines-in-active-region nil org-occur-hook '(org-first-headline-recenter) org-metadown-hook '(org-babel-pop-to-session-maybe) org-link-parameters '(("attachment" :follow org-attach-follow :complete org-attach-complete-link) ("id" :follow org-id-open) ("treemacs" :store treemacs-store-org-link) ("eww" :follow org-eww-open :store org-eww-store-link) ("rmail" :follow org-rmail-open :store org-rmail-store-link) ("mhe" :follow org-mhe-open :store org-mhe-store-link) ("irc" :follow org-irc-visit :store org-irc-store-link :export org-irc-export) ("info" :follow org-info-open :export org-info-export :store org-info-store-link) ("gnus" :follow org-gnus-open :store org-gnus-store-link) ("docview" :follow org-docview-open :export org-docview-export :store org-docview-store-link) ("bibtex" :follow org-bibtex-open :store org-bibtex-store-link) ("bbdb" :follow org-bbdb-open :export org-bbdb-export :complete org-bbdb-complete-link :store org-bbdb-store-link) ("w3m" :store org-w3m-store-link) ("file+sys") ("file+emacs") ("shell" :follow org-link--open-shell) ("news" :follow #[514 "\301\300\302Q\"\207" ["news" browse-url ":"] 6 "\n\n(fn URL ARG)"] ) ("mailto" :follow #[514 "\301\300\302Q\"\207" ["mailto" browse-url ":"] 6 "\n\n(fn URL ARG)"] ) ("https" :follow #[514 "\301\300\302Q\"\207" ["https" browse-url ":"] 6 "\n\n(fn URL ARG)"] ) ("http" :follow #[514 "\301\300\302Q\"\207" ["http" browse-url ":"] 6 "\n\n(fn URL ARG)"] ) ("ftp" :follow #[514 "\301\300\302Q\"\207" ["ftp" browse-url ":"] 6 "\n\n(fn URL ARG)"] ) ("help" :follow org-link--open-help) ("file" :complete org-link-complete-file) ("elisp" :follow org-link--open-elisp) ("doi" :follow org-link--open-doi)) org-metaup-hook '(org-babel-load-in-session-maybe) org-outline-path-complete-in-steps nil )