Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  file-name-nondirectory(nil)
  insert-file-contents("~/News/drafts/drafts/818")
  byte-code("..." [file coding-system-for-read auto-mode-alist file-name-coding-system nnmail-pathname-coding-system nnmail-file-coding-system mm-auto-mode-alist insert-file-contents t] 3)
  nnmail-find-file("~/News/drafts/drafts/818")
  nndraft-request-article(818 "drafts" "" #<buffer " *nntpd*">)
  nndraft-retrieve-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926) "drafts" "" t)
  gnus-retrieve-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926) "nndraft:drafts" t)
  gnus-fetch-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926))
  gnus-select-newsgroup("nndraft:drafts" nil nil)
  gnus-summary-read-group-1("nndraft:drafts" nil t nil nil nil)
  gnus-summary-read-group("nndraft:drafts" nil t nil nil nil nil)
  gnus-group-read-group(nil t)
  gnus-group-select-group(nil)
  gnus-topic-select-group(nil)
  call-interactively(gnus-topic-select-group)
  recursive-edit()
  byte-code("..." [buffer-read-only noninteractive debugger-buffer middlestart debugger-args debugger-batch-max-lines pop-to-buffer debugger-mode debugger-setup-buffer count-lines 2 "...\n" message buffer-string kill-emacs debug backtrace-debug 3 t debugger-reenable "" nil recursive-edit standard-output] 3)
  debug(error (wrong-type-argument stringp nil))
  file-name-nondirectory(nil)
  insert-file-contents("~/News/drafts/drafts/818")
  byte-code("..." [file coding-system-for-read auto-mode-alist file-name-coding-system nnmail-pathname-coding-system nnmail-file-coding-system mm-auto-mode-alist insert-file-contents t] 3)
  nnmail-find-file("~/News/drafts/drafts/818")
  nndraft-request-article(818 "drafts" "" #<buffer " *nntpd*">)
  nndraft-retrieve-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926) "drafts" "" t)
  gnus-retrieve-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926) "nndraft:drafts" t)
  gnus-cache-retrieve-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926) "nndraft:drafts" t)
  gnus-retrieve-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926) "nndraft:drafts" t)
  gnus-fetch-headers((604 719 725 726 728 730 731 732 733 735 741 743 747 751 754 783 785 787 795 796 816 817 818 819 822 827 829 831 836 838 841 842 846 848 851 852 855 874 885 894 896 903 908 917 920 923 926))
  gnus-select-newsgroup("nndraft:drafts" nil nil)
  gnus-summary-read-group-1("nndraft:drafts" nil t nil nil nil)
  gnus-summary-read-group("nndraft:drafts" nil t nil nil nil nil)
  gnus-group-read-group(nil t)
  gnus-group-select-group(nil)
  gnus-topic-select-group(nil)
  call-interactively(gnus-topic-select-group)