Emacs : GNU Emacs 26.3 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.20) Package: Org mode version 9.1.9 (release_9.1.9-65-g5e4542 @ /home/cwebber/.guix-profile/share/emacs/26.3/lisp/org/) Not sure if this will work on Windows because it uses posix'y permissions.... but anyway I found that the ODT exporter did not work on Guix because the styles.xml got copied over as read-only. This fixes it for me. I've already done copyright assignment for the "AM/PM support on the agenda timegrid" patch I sent in 2010; I assume this has not expired over the last decade. If you check the use-by date and my copyright assignment has somehow gone moldy let me know and I'll be happy to update it. - Chris