Debugger entered--Lisp error: (wrong-type-argument char-or-string-p nil)
  format-spec(nil ((116 . #("Mis-shapen chaos of well-seeming forms!" 0 39 (:parent (#("Mis-shapen chaos of well-seeming forms!" 0 39 (:parent #7)))))) (97 . #("Romeo" 0 5 (:parent (#("Romeo" 0 5 (:parent #8)))))) (116 . #("Mis-shapen chaos of well-seeming forms!" 0 39 (:parent (#("Mis-shapen chaos of well-seeming forms!" 0 39 (:parent #9)))))) (115 . "") (107 . "") (100 . "") (99 . "Emacs 28.0.50 (Org mode 9.3.6)") (108 . "english") (76 . "English") (68 #("1580" 0 4 (:parent #13)))))
  (concat (if (and with-subject (not (eq with-subject t))) (progn (format "\\KOMAoption{subject}{%s}\n" (if (symbolp with-subject) with-subject (mapconcat #'symbol-name with-subject ","))))) (format-spec hyperref-template spec) "\\begin{document}\n\n" (if subject (progn (format "\\setkomavar{subject}{%s}\n" subject))) (if title (progn (format "\\setkomavar{title}{%s}\n" title))) (if (or (org-string-nw-p title) (org-string-nw-p subject)) (progn "\n")))
  (let* ((with-subject (plist-get info :with-subject)) (with-title (plist-get info :with-title)) (title-as-subject (and with-subject (plist-get info :with-title-as-subject))) (subject* (org-string-nw-p (org-export-data (plist-get info :subject) info))) (title* (and with-title (org-string-nw-p (org-export-data (plist-get info :title) info)))) (subject (cond ((not with-subject) nil) (title-as-subject (or subject* title*)) (t subject*))) (title (cond ((not with-title) nil) (title-as-subject (and subject* title*)) (t title*))) (hyperref-template (plist-get info :latex-hyperref-template)) (spec (append (list (cons 116 (or title subject ""))) (org-latex--format-spec info)))) (concat (if (and with-subject (not (eq with-subject t))) (progn (format "\\KOMAoption{subject}{%s}\n" (if (symbolp with-subject) with-subject (mapconcat #'symbol-name with-subject ","))))) (format-spec hyperref-template spec) "\\begin{document}\n\n" (if subject (progn (format "\\setkomavar{subject}{%s}\n" subject))) (if title (progn (format "\\setkomavar{title}{%s}\n" title))) (if (or (org-string-nw-p title) (org-string-nw-p subject)) (progn "\n"))))
  (concat (and (plist-get info :time-stamp-file) (format-time-string "%% Created %Y-%m-%d %a %H:%M\n")) (org-latex--insert-compiler info) (org-latex-make-preamble info) (org-koma-letter--build-settings 'global info) (mapconcat #'(lambda (file) (format "\\LoadLetterOption{%s}\n" file)) (split-string (or (plist-get info :lco) "")) "") (org-koma-letter--build-settings 'buffer info) (format "\\date{%s}\n" (org-export-data (org-export-get-date info) info)) (let* ((with-subject (plist-get info :with-subject)) (with-title (plist-get info :with-title)) (title-as-subject (and with-subject (plist-get info :with-title-as-subject))) (subject* (org-string-nw-p (org-export-data (plist-get info :subject) info))) (title* (and with-title (org-string-nw-p (org-export-data (plist-get info :title) info)))) (subject (cond ((not with-subject) nil) (title-as-subject (or subject* title*)) (t subject*))) (title (cond ((not with-title) nil) (title-as-subject (and subject* title*)) (t title*))) (hyperref-template (plist-get info :latex-hyperref-template)) (spec (append (list (cons 116 (or title subject ""))) (org-latex--format-spec info)))) (concat (if (and with-subject (not (eq with-subject t))) (progn (format "\\KOMAoption{subject}{%s}\n" (if (symbolp with-subject) with-subject (mapconcat ... with-subject ","))))) (format-spec hyperref-template spec) "\\begin{document}\n\n" (if subject (progn (format "\\setkomavar{subject}{%s}\n" subject))) (if title (progn (format "\\setkomavar{title}{%s}\n" title))) (if (or (org-string-nw-p title) (org-string-nw-p subject)) (progn "\n")))) (let ((keyword-val (plist-get info :to-address)) (heading-val (org-koma-letter--get-tagged-contents 'to))) (format "\\begin{letter}{%%\n%s}\n\n" (org-koma-letter--add-latex-newlines (or (if (plist-get info :special-headings) (or heading-val keyword-val) (or keyword-val heading-val)) "\\mbox{}")))) (format "\\opening{%s}\n\n" (org-koma-letter--keyword-or-headline :opening #'(lambda (h i) (not (org-koma-letter--special-tag h i))) info)) contents (format "\\closing{%s}\n" (org-koma-letter--keyword-or-headline :closing #'(lambda (h i) (let ((special-tag ...)) (and special-tag (string= "closing" special-tag)))) info)) (org-koma-letter--special-contents-inline (plist-get info :special-tags-after-closing) info) "\n\\end{letter}\n" (org-koma-letter--special-contents-inline (plist-get info :special-tags-after-letter) info) "\n\\end{document}")
  org-koma-letter-template(#("\n\n\n\\begin{verse}\nThen plai..." 17 62 (:parent (verse-block ... ...)) 65 102 (:parent (verse-block ... ...)) 105 145 (:parent (verse-block ... ...)) 148 193 (:parent (verse-block ... ...)) 196 238 (:parent (verse-block ... ...)) 241 284 (:parent (verse-block ... ...)) 287 330 (:parent (verse-block ... ...)) 333 370 (:parent (verse-block ... ...)) ...) (:export-options nil :back-end #s(org-export-backend :name koma-letter :parent latex :transcoders (... ... ... ... ...) :options (... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ...) :filters nil :blocks nil :menu (107 "Export with KOMA Scrlttr2" ...)) :translate-alist ((export-block . org-koma-letter-export-block) (export-snippet . org-koma-letter-export-snippet) (headline . org-koma-letter-headline) (keyword . org-koma-letter-keyword) (template . org-koma-letter-template) (bold . org-latex-bold) (center-block . org-latex-center-block) (clock . org-latex-clock) (code . org-latex-code) (drawer . org-latex-drawer) (dynamic-block . org-latex-dynamic-block) (entity . org-latex-entity) (example-block . org-latex-example-block) (export-block . org-latex-export-block) (export-snippet . org-latex-export-snippet) (fixed-width . org-latex-fixed-width) (footnote-definition . org-latex-footnote-definition) (footnote-reference . org-latex-footnote-reference) (headline . org-latex-headline) (horizontal-rule . org-latex-horizontal-rule) (inline-src-block . org-latex-inline-src-block) (inlinetask . org-latex-inlinetask) (italic . org-latex-italic) (item . org-latex-item) (keyword . org-latex-keyword) (latex-environment . org-latex-latex-environment) ...) :exported-data #<hash-table eq 61/4001 0x155cb7abc4b9> :input-buffer "LearnKomaLetter.org" :input-file "/mnt/Data/ActiveFiles/Lear..." :latex-class "default-koma-letter" :lco "DINmtext" :author (#("Romeo" 0 5 ...)) :author-changed-in-buffer-p "Romeo" :from-address "" :phone-number "" :url "" ...))
  org-export-as(koma-letter nil nil nil (:output-file "LearnKomaLetter.tex"))
  org-export-to-file(koma-letter "LearnKomaLetter.tex" nil nil nil nil nil (lambda (file) (org-latex-compile file)))
  (let ((file (org-export-output-file-name ".tex" subtreep)) (org-koma-letter-special-contents)) (org-export-to-file 'koma-letter file async subtreep visible-only body-only ext-plist #'(lambda (file) (org-latex-compile file))))
  org-koma-letter-export-to-pdf(nil nil nil nil)
  (org-open-file (org-koma-letter-export-to-pdf nil s v b))
  (if a (org-koma-letter-export-to-pdf t s v b) (org-open-file (org-koma-letter-export-to-pdf nil s v b)))
  (lambda (a s v b) (if a (org-koma-letter-export-to-pdf t s v b) (org-open-file (org-koma-letter-export-to-pdf nil s v b))))(nil nil nil nil)
  org-export-dispatch(nil)
  funcall-interactively(org-export-dispatch nil)
  call-interactively(org-export-dispatch nil nil)
  command-execute(org-export-dispatch)