Trying to just read Xavier's email message in Gnus, I get the following backtrace (with unprintable characters replaced by periods) - to me, this looks like a bug somewhere, but not sure where:
Debugger entered--Lisp error: (error "Before first headline at position 114 in buffer *fontification*<2>") signal(error ("Before first headline at position 114 in buffer *fontification*<2>")) error("Before first headline at position %d in buffer %s" 114 #<buffer *fontification*<2>>) (condition-case nil (outline-back-to-heading invisible-ok) (error (error "Before first headline at position %d in buffer %s" (point) (current-buffer)))) org-back-to-heading(t) (save-excursion (org-back-to-heading t) (if (symbolp tprop) (put-text-property (point) (or (outline-next-heading) (point-max)) tprop p) (mapc (function (lambda (al) (save-excursion (put-text-property (point-at-bol) (or ... ...) (car al) (funcall ... p))))) tprop))) org-refresh-property(((effort . identity) (effort-minutes . org-duration-string-to-minutes)) "%^{effort|1:00|0:30|0:05|0:15|2:00|3:00|4:00}") (while (re-search-forward (concat "^[ ]*:" dprop ": +\\(.*\\)[ ]*$") nil t) (org-refresh-property tprop (org-match-string-no-properties 1))) (save-restriction (widen) (goto-char (point-min)) (while (re-search-forward (concat "^[ ]*:" dprop ": +\\(.*\\)[ ]*$") nil t) (org-refresh-property tprop (org-match-string-no-properties 1)))) (save-excursion (save-restriction (widen) (goto-char (point-min)) (while (re-search-forward (concat "^[ ]*:" dprop ": +\\(.*\\)[ ]*$") nil t) (org-refresh-property tprop (org-match-string-no-properties 1))))) (progn (save-excursion (save-restriction (widen) (goto-char (point-min)) (while (re-search-forward (concat "^[ ]*:" dprop ": +\\(.*\\)[ ]*$") nil t) (org-refresh-property tprop (org-match-string-no-properties 1)))))) (unwind-protect (progn (save-excursion (save-restriction (widen) (goto-char (point-min)) (while (re-search-forward (concat "^[ ]*:" dprop ": +\\(.*\\)[ ]*$") nil t) (org-refresh-property tprop (org-match-string-no-properties 1)))))) (if modified nil (restore-buffer-modified-p nil))) (let* ((modified (buffer-modified-p)) (buffer-undo-list t) (inhibit-read-only t) (inhibit-modification-hooks t)) (unwind-protect (progn (save-excursion (save-restriction (widen) (goto-char (point-min)) (while (re-search-forward (concat "^[ ]*:" dprop ": +\\(.*\\)[ ]*$") nil t) (org-refresh-property tprop (org-match-string-no-properties 1)))))) (if modified nil (restore-buffer-modified-p nil)))) (let ((case-fold-search t) (inhibit-read-only t)) (let* ((modified (buffer-modified-p)) (buffer-undo-list t) (inhibit-read-only t) (inhibit-modification-hooks t)) (unwind-protect (progn (save-excursion (save-restriction (widen) (goto-char (point-min)) (while (re-search-forward ... nil t) (org-refresh-property tprop ...))))) (if modified nil (restore-buffer-modified-p nil))))) org-refresh-properties("Effort" ((effort . identity) (effort-minutes . org-duration-string-to-minutes))) org-refresh-effort-properties() (let ((buffer-undo-list t) (inhibit-modification-hooks t)) (and org-startup-with-beamer-mode (org-beamer-mode)) (if org-startup-align-all-tables (progn (org-table-map-tables (quote org-table-align) (quote quietly)))) (if org-startup-with-inline-images (progn (org-display-inline-images))) (if org-startup-with-latex-preview (progn (org-toggle-latex-fragment))) (if org-inhibit-startup-visibility-stuff nil (org-set-startup-visibility)) (org-refresh-effort-properties)) (unwind-protect (let ((buffer-undo-list t) (inhibit-modification-hooks t)) (and org-startup-with-beamer-mode (org-beamer-mode)) (if org-startup-align-all-tables (progn (org-table-map-tables (quote org-table-align) (quote quietly)))) (if org-startup-with-inline-images (progn (org-display-inline-images))) (if org-startup-with-latex-preview (progn (org-toggle-latex-fragment))) (if org-inhibit-startup-visibility-stuff nil (org-set-startup-visibility)) (org-refresh-effort-properties)) (set-buffer-modified-p --was-modified)) (let ((--was-modified (buffer-modified-p))) (unwind-protect (let ((buffer-undo-list t) (inhibit-modification-hooks t)) (and org-startup-with-beamer-mode (org-beamer-mode)) (if org-startup-align-all-tables (progn (org-table-map-tables (quote org-table-align) (quote quietly)))) (if org-startup-with-inline-images (progn (org-display-inline-images))) (if org-startup-with-latex-preview (progn (org-toggle-latex-fragment))) (if org-inhibit-startup-visibility-stuff nil (org-set-startup-visibility)) (org-refresh-effort-properties)) (set-buffer-modified-p --was-modified))) (if org-inhibit-startup nil (let ((--was-modified (buffer-modified-p))) (unwind-protect (let ((buffer-undo-list t) (inhibit-modification-hooks t)) (and org-startup-with-beamer-mode (org-beamer-mode)) (if org-startup-align-all-tables (progn (org-table-map-tables (quote org-table-align) (quote quietly)))) (if org-startup-with-inline-images (progn (org-display-inline-images))) (if org-startup-with-latex-preview (progn (org-toggle-latex-fragment))) (if org-inhibit-startup-visibility-stuff nil (org-set-startup-visibility)) (org-refresh-effort-properties)) (set-buffer-modified-p --was-modified)))) (let ((delay-mode-hooks t)) (outline-mode) (setq major-mode (quote org-mode)) (setq mode-name "Org") (progn (if (get (quote outline-mode) (quote mode-class)) (put (quote org-mode) (quote mode-class) (get (quote outline-mode) (quote mode-class)))) (if (keymap-parent org-mode-map) nil (set-keymap-parent org-mode-map (current-local-map))) (let ((parent (char-table-parent org-mode-syntax-table))) (if (and parent (not (eq parent (standard-syntax-table)))) nil (set-char-table-parent org-mode-syntax-table (syntax-table)))) (if (or (abbrev-table-get org-mode-abbrev-table :parents) (eq org-mode-abbrev-table local-abbrev-table)) nil (abbrev-table-put org-mode-abbrev-table :parents (list local-abbrev-table)))) (use-local-map org-mode-map) (set-syntax-table org-mode-syntax-table) (setq local-abbrev-table org-mode-abbrev-table) (if nil (if (boundp (quote outline-mode-menu-heading)) (progn (easy-menu-remove outline-mode-menu-heading) (easy-menu-remove outline-mode-menu-show) (easy-menu-remove outline-mode-menu-hide))) (define-key org-mode-map [menu-bar headings] (quote undefined)) (define-key org-mode-map [menu-bar hide] (quote undefined)) (define-key org-mode-map [menu-bar show] (quote undefined))) (org-load-modules-maybe) (easy-menu-add org-org-menu) (easy-menu-add org-tbl-menu) (org-install-agenda-files-menu) (if org-descriptive-links (add-to-invisibility-spec (quote (org-link)))) (add-to-invisibility-spec (quote (org-cwidth))) (add-to-invisibility-spec (quote (org-hide-block . t))) (if nil (progn (org-set-local (quote line-move-ignore-invisible) t))) (org-set-local (quote outline-regexp) org-outline-regexp) (org-set-local (quote outline-level) (quote org-outline-level)) (setq bidi-paragraph-direction (quote left-to-right)) (if (and org-ellipsis (fboundp (quote set-display-table-slot)) (boundp (quote buffer-display-table)) (fboundp (quote make-glyph-code))) (progn (if org-display-table nil (setq org-display-table (make-display-table))) (set-display-table-slot org-display-table 4 (vconcat (mapcar (function (lambda ... ...)) (if (stringp org-ellipsis) org-ellipsis "...")))) (setq buffer-display-table org-display-table))) (org-set-regexps-and-options) (org-set-font-lock-defaults) (if (and org-tag-faces (not org-tags-special-faces-re)) (progn (org-set-tag-faces (quote org-tag-faces) org-tag-faces))) (org-set-local (quote calc-embedded-open-mode) "# ") (modify-syntax-entry 64 "w") (modify-syntax-entry 34 "\"") (modify-syntax-entry 92 "_") (modify-syntax-entry 126 "_") (if org-startup-truncated (setq truncate-lines t)) (if org-startup-indented (progn (require (quote org-indent)) (org-indent-mode 1))) (org-set-local (quote font-lock-unfontify-region-function) (quote org-unfontify-region)) (org-set-local (quote org-table-may-need-update) t) (org-add-hook (quote before-change-functions) (quote org-before-change-function) nil (quote local)) (org-add-hook (quote kill-buffer-hook) (quote org-check-running-clock) nil (quote local)) (org-macro-initialize-templates) (org-update-radio-target-regexp) (org-set-local (quote indent-line-function) (quote org-indent-line)) (org-set-local (quote indent-region-function) (quote org-indent-region)) (org-setup-filling) (org-setup-comments-handling) (org-element-cache-reset) (org-set-local (quote beginning-of-defun-function) (quote org-backward-element)) (org-set-local (quote end-of-defun-function) (function (lambda nil (if (not (org-at-heading-p)) (org-forward-element) (org-forward-element) (forward-char -1))))) (org-set-local (quote next-error-function) (quote org-occur-next-match)) (if org-enforce-todo-dependencies (add-hook (quote org-blocker-hook) (quote org-block-todo-from-children-or-siblings-or-parent)) (remove-hook (quote org-blocker-hook) (quote org-block-todo-from-children-or-siblings-or-parent))) (if org-enforce-todo-checkbox-dependencies (add-hook (quote org-blocker-hook) (quote org-block-todo-from-checkboxes)) (remove-hook (quote org-blocker-hook) (quote org-block-todo-from-checkboxes))) (org-set-local (quote align-mode-rules-list) (quote ((org-in-buffer-settings (regexp . "^[ ]*#\\+[A-Z_]+:\\(\\s-*\\)\\S-+") (modes quote (org-mode)))))) (org-set-local (quote imenu-create-index-function) (quote org-imenu-get-tree)) ...) (progn (make-local-variable (quote delay-mode-hooks)) (let ((delay-mode-hooks t)) (outline-mode) (setq major-mode (quote org-mode)) (setq mode-name "Org") (progn (if (get (quote outline-mode) (quote mode-class)) (put (quote org-mode) (quote mode-class) (get (quote outline-mode) (quote mode-class)))) (if (keymap-parent org-mode-map) nil (set-keymap-parent org-mode-map (current-local-map))) (let ((parent (char-table-parent org-mode-syntax-table))) (if (and parent (not (eq parent ...))) nil (set-char-table-parent org-mode-syntax-table (syntax-table)))) (if (or (abbrev-table-get org-mode-abbrev-table :parents) (eq org-mode-abbrev-table local-abbrev-table)) nil (abbrev-table-put org-mode-abbrev-table :parents (list local-abbrev-table)))) (use-local-map org-mode-map) (set-syntax-table org-mode-syntax-table) (setq local-abbrev-table org-mode-abbrev-table) (if nil (if (boundp (quote outline-mode-menu-heading)) (progn (easy-menu-remove outline-mode-menu-heading) (easy-menu-remove outline-mode-menu-show) (easy-menu-remove outline-mode-menu-hide))) (define-key org-mode-map [menu-bar headings] (quote undefined)) (define-key org-mode-map [menu-bar hide] (quote undefined)) (define-key org-mode-map [menu-bar show] (quote undefined))) (org-load-modules-maybe) (easy-menu-add org-org-menu) (easy-menu-add org-tbl-menu) (org-install-agenda-files-menu) (if org-descriptive-links (add-to-invisibility-spec (quote (org-link)))) (add-to-invisibility-spec (quote (org-cwidth))) (add-to-invisibility-spec (quote (org-hide-block . t))) (if nil (progn (org-set-local (quote line-move-ignore-invisible) t))) (org-set-local (quote outline-regexp) org-outline-regexp) (org-set-local (quote outline-level) (quote org-outline-level)) (setq bidi-paragraph-direction (quote left-to-right)) (if (and org-ellipsis (fboundp (quote set-display-table-slot)) (boundp (quote buffer-display-table)) (fboundp (quote make-glyph-code))) (progn (if org-display-table nil (setq org-display-table (make-display-table))) (set-display-table-slot org-display-table 4 (vconcat (mapcar (function ...) (if ... org-ellipsis "...")))) (setq buffer-display-table org-display-table))) (org-set-regexps-and-options) (org-set-font-lock-defaults) (if (and org-tag-faces (not org-tags-special-faces-re)) (progn (org-set-tag-faces (quote org-tag-faces) org-tag-faces))) (org-set-local (quote calc-embedded-open-mode) "# ") (modify-syntax-entry 64 "w") (modify-syntax-entry 34 "\"") (modify-syntax-entry 92 "_") (modify-syntax-entry 126 "_") (if org-startup-truncated (setq truncate-lines t)) (if org-startup-indented (progn (require (quote org-indent)) (org-indent-mode 1))) (org-set-local (quote font-lock-unfontify-region-function) (quote org-unfontify-region)) (org-set-local (quote org-table-may-need-update) t) (org-add-hook (quote before-change-functions) (quote org-before-change-function) nil (quote local)) (org-add-hook (quote kill-buffer-hook) (quote org-check-running-clock) nil (quote local)) (org-macro-initialize-templates) (org-update-radio-target-regexp) (org-set-local (quote indent-line-function) (quote org-indent-line)) (org-set-local (quote indent-region-function) (quote org-indent-region)) (org-setup-filling) (org-setup-comments-handling) (org-element-cache-reset) (org-set-local (quote beginning-of-defun-function) (quote org-backward-element)) (org-set-local (quote end-of-defun-function) (function (lambda nil (if (not (org-at-heading-p)) (org-forward-element) (org-forward-element) (forward-char -1))))) (org-set-local (quote next-error-function) (quote org-occur-next-match)) (if org-enforce-todo-dependencies (add-hook (quote org-blocker-hook) (quote org-block-todo-from-children-or-siblings-or-parent)) (remove-hook (quote org-blocker-hook) (quote org-block-todo-from-children-or-siblings-or-parent))) (if org-enforce-todo-checkbox-dependencies (add-hook (quote org-blocker-hook) (quote org-block-todo-from-checkboxes)) (remove-hook (quote org-blocker-hook) (quote org-block-todo-from-checkboxes))) (org-set-local (quote align-mode-rules-list) (quote ((org-in-buffer-settings (regexp . "^[ ]*#\\+[A-Z_]+:\\(\\s-*\\)\\S-+") (modes quote (org-mode)))))) (org-set-local (quote imenu-create-index-function) (quote org-imenu-get-tree)) ...)) org-mode() mm-display-inline-fontify((#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil) org-mode) mm-display-org-inline((#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil)) mm-display-inline((#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil)) mm-display-part((#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil) t) byte-code("\203..\306\211A.\242 \"\203..\307\300\310\"\210\202..\n\211.\205\".\311\312!!)\203/.r\nq\210\f)\2020.\f\203:.\306\313 \"\204x.\314.!?\205T.\315.8?\206T.\315.8@\316\232\206T.\317.!\211.*\203x.\320.!\203x.\321.!\203l.\322.!\204r.\323 !\203x.\324.+\202\231...\325.\211.@;\203\210..@\202\214..A@@)\326\"@)\327\232\203\231.\324.,.-GT\310..\211./.B.-B.-.+\203\357...\325.\211.@;\203\277..@\202\303..A@@)\326\"@)\330\232\203\357.\331\332n\204\327.\333\202\355.o\204\350.`S\206\341.`Sf\332=\203\354.\334\202\355.\335\"\210.+\203..\336 !\203.../.0=\203..\337../.+\206...*\205...,C#\210\340 \210\324.1`...+\203\231..1\203..\341y\210`...2\212\310\342\343\217\210.3).4.5\344\345!\203^..6\211.\205O.\311\312!!)\203^.r.6q\210.7)\202`..7\211.8\204j.\324\202\204..9;\203y.\306.9.8\"\202\204..9:\205\204..8.9\235?\205\212..:).:\346.\324\"\210+db\210\202\270..,\203\270..*\203\270..1\203\256.\341y\210`..\340 \210\347.!\210db\210\212\214..`}\210..;=\203\340.\350\310\335\211.\211.@;\203\327..@\202\333..A@@)$\2021.\310.<.;\310.=\211.>\203...>@\211.=;\204 ..=A@@\351\232\204 ..=.<B.<.>A\211.>\204\356.*\350\310..<>G.<G.\211.@;\203*..@\202...A@@)$),\207" [ignored type gnus-summary-buffer buffer gnus-inhibit-images handle string-match throw nil buffer-live-p get-buffer "\\`image/" mm-inline-override-p 4 "inline" mm-attachment-override-p mm-automatic-display-p mm-inlinable-p mm-inlined-p mm-automatic-external-display-p t split-string "/" "text" "message" insert-char 10 2 0 1 gnus-unbuttonized-mime-type-p gnus-insert-mime-button gnus-article-insert-newline -1 (set-buffer gnus-summary-buffer) ((error)) derived-mode-p gnus-article-mode mm-display-part mm-display-inline gnus-treat-article "application/pgp-signature" not-attachment display text gnus-article-mime-handle-alist beg id gnus-mime-buttonized-part-id move ...] 6) gnus-mime-display-single((#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil)) gnus-mime-display-part((#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil)) mapcar(gnus-mime-display-part ((#<buffer *mm-uu*-700623> ("text/plain" (charset . gnus-decoded)) nil (lambda nil (let ((inhibit-read-only t)) (delete-region #<marker (moves after insertion) at 4649 in *Article gmane.emacs.orgmode*> #<marker at 4733 in *Article gmane.emacs.orgmode*>))) nil nil nil nil) (#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil) (#<buffer *mm-uu*-860944> ("text/plain" (charset . gnus-decoded)) nil nil nil nil nil nil) (#<buffer *mm-uu*-640953> ("text/x-org") nil nil nil nil nil nil) (#<buffer *mm-uu*-263236> ("text/plain" (charset . gnus-decoded)) nil nil nil nil nil nil))) gnus-mime-display-mixed(((#<buffer *mm-uu*-700623> ("text/plain" (charset . gnus-decoded)) nil (lambda nil (let ((inhibit-read-only t)) (delete-region #<marker (moves after insertion) at 4649 in *Article gmane.emacs.orgmode*> #<marker at 4733 in *Article gmane.emacs.orgmode*>))) nil nil nil nil) (#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil) (#<buffer *mm-uu*-860944> ("text/plain" (charset . gnus-decoded)) nil nil nil nil nil nil) (#<buffer *mm-uu*-640953> ("text/x-org") nil nil nil nil nil nil) (#<buffer *mm-uu*-263236> ("text/plain" (charset . gnus-decoded)) nil nil nil nil nil nil))) gnus-mime-display-part(("multipart/mixed" (#<buffer *mm-uu*-700623> ("text/plain" (charset . gnus-decoded)) nil (lambda nil (let ((inhibit-read-only t)) (delete-region #<marker (moves after insertion) at 4649 in *Article gmane.emacs.orgmode*> #<marker at 4733 in *Article gmane.emacs.orgmode*>))) nil nil nil nil) (#<buffer *mm-uu*-906540> ("text/x-org") nil nil nil nil nil nil) (#<buffer *mm-uu*-860944> ("text/plain" (charset . gnus-decoded)) nil nil nil nil nil nil) (#<buffer *mm-uu*-640953> ("text/x-org") nil nil nil nil nil nil) (#<buffer *mm-uu*-263236> ("text/plain" (charset . gnus-decoded)) nil nil nil nil nil nil))) gnus-display-mime() gnus-article-prepare-display() gnus-article-prepare(96536 nil) gnus-summary-display-article(96536) gnus-summary-next-page(nil) funcall-interactively(gnus-summary-next-page nil) call-interactively(gnus-summary-next-page nil nil) command-execute(gnus-summary-next-page)