In an up to date master branch, I'm noticing a bug in ODT export: if
org-export-with-section-numbers is set to nil, ox-odt exports headlines as
plain-text paragraphs.

With emacs -q, evaluate:

(setq org-export-with-section-numbers nil
      org-export-with-toc nil
      org-export-preserve-breaks nil
      org-export-email-info nil
)

then try to export to odt using the builtin org(emacs 25.1, so org 8.2.10,
in my case).  Headlines should export fine.  Now try with a recent git org;
headlines should fail to export.  At least, that's my experience.  I tried
to bisect by checking out old commits and running make-all, then
org-reload; but the problem persisted even for pretty old commits, so I
think I'm not doing it right.  Would very much welcome any help! thanks,
Matt