There is a potential bug regarging how footnotes on headers are converted to LaTeX. Consider the following org file: ------start-of-file----------- #+AUTHOR: Me #+LATEX_HEADER: \usepackage{titlesec} * Header1[fn:1] * Footnotes [fn:1]Lorem ipsum ------end-of-file-------------- When converting to LaTeX the header is exported as: \section{Header1\footnote{Lorem ipsum}} I believe the proper output should be: \section{Header1}\footnote{Lorem ipsum} Notice that the footnote is placed after the closing bracket segment instead of being part of the header section. Excuse me for my ignorance of LaTeX, for I cannot definitively say which one is correct(maybe they both are) but the second output seems more logical. Both versions get compiled correctly, however when adding the package "titlesec" the first version results in failed compilation (the following error message seems to signify some kind of infinite recursion/loop): -----error-message-during-compilation----- Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding): (hyperref)                removing `\@ifnextchar' on input line 32. ! TeX capacity exceeded, sorry [input stack size=5000]. \reserved@a ->\def \reserved@a                                *{\ttl@assign@i {\@tempskipb }}\reserved@a l.32 \section{Header1\footnote{Lorem ipsum}} !  ==> Fatal error occurred, no output PDF file produced! ------------------------------------------ If both versions are correct then the bug obviously lies in the "titlesec" package. However, as I previously said, I don't know if that is the case. It is possible that this happens with other packages too. I have not tested any other packages that deal with headers. I have also tested this on org version 9.4 and the same output is produced. I have attached the org file, the tex output file that leads to the bug and the output log of the compilation process. ========================================== Emacs  : GNU Emacs 27.1 (build 1, x86_64-redhat-linux-gnu, X toolkit, cairo version 1.16.0, Xaw3d scroll bars)  of 2020-08-21 Package: Org mode version 9.3 (release_9.3 @ /usr/share/emacs/27.1/lisp/org/) current state: ============== (setq  org-src-mode-hook '(org-src-babel-configure-edit-buffer org-src-mode-configure-edit-buffer)  org-link-shell-confirm-function 'yes-or-no-p  org-metadown-hook '(org-babel-pop-to-session-maybe)  org-clock-out-hook '(org-clock-remove-empty-clock-drawer)  org-html-format-inlinetask-function 'org-html-format-inlinetask-default-function  org-odt-format-headline-function 'org-odt-format-headline-default-function  org-ascii-format-inlinetask-function 'org-ascii-format-inlinetask-default  org-mode-hook '(#[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-odt-format-drawer-function #[514 "\207" [] 3 "\n\n(fn NAME CONTENTS)"]  org-archive-hook '(org-attach-archive-delete-maybe)  org-confirm-elisp-link-function 'yes-or-no-p  org-agenda-before-write-hook '(org-agenda-add-entry-text)  org-metaup-hook '(org-babel-load-in-session-maybe)  org-bibtex-headline-format-function #[257 "\300\236A\207" [:title] 3 "\n\n(fn ENTRY)"]  org-latex-format-drawer-function #[514 "\207" [] 3 "\n\n(fn _ CONTENTS)"]  org-babel-pre-tangle-hook '(save-buffer)  org-tab-first-hook '(org-babel-hide-result-toggle-maybe org-babel-header-arg-expand)  org-ascii-format-drawer-function #[771 "\207" [] 4 "\n\n(fn NAME CONTENTS WIDTH)"]  org-occur-hook '(org-first-headline-recenter)  org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-show-empty-lines org-optimize-window-after-visibility-change)  org-speed-command-hook '(org-speed-command-activate org-babel-speed-command-activate)  org-odt-format-inlinetask-function 'org-odt-format-inlinetask-default-function  org-confirm-shell-link-function 'yes-or-no-p  org-link-parameters '(("attachment" :follow org-attach-open-link :export org-attach-export-link :complete org-attach-complete-link)                ("id" :follow org-id-open) ("eww" :follow eww :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 #[257 "\301\300\302Q!\207" ["news" browse-url ":"] 5 "\n\n(fn URL)"])                ("mailto" :follow #[257 "\301\300\302Q!\207" ["mailto" browse-url ":"] 5 "\n\n(fn URL)"])                ("https" :follow #[257 "\301\300\302Q!\207" ["https" browse-url ":"] 5 "\n\n(fn URL)"])                ("http" :follow #[257 "\301\300\302Q!\207" ["http" browse-url ":"] 5 "\n\n(fn URL)"])                ("ftp" :follow #[257 "\301\300\302Q!\207" ["ftp" browse-url ":"] 5 "\n\n(fn URL)"])                ("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-latex-format-headline-function 'org-latex-format-headline-default-function  org-link-elisp-confirm-function 'yes-or-no-p  org-latex-format-inlinetask-function 'org-latex-format-inlinetask-default-function  org-html-format-drawer-function #[514 "\207" [] 3 "\n\n(fn NAME CONTENTS)"]  org-html-format-headline-function 'org-html-format-headline-default-function  )