I found the question, take an easy example: * Title1 *** Title2 Test[fn:6] * Footnotes [fn:6]
If there's a footnote is empty (or just following a space or so), the exporter will just return "org-trim: Wrong type argument: stringp, nil" I think this is a bug because the exporter should told user "there're some footnotes are empty" instead of an human-unreadable error message. kuanyui 20140513 0014 GMT+8