I wasn't sure who to send this to.

An element cannot be parsed line XX  # When filling text (fill-paragraph)
undefined org-clock-line-re          # when editing \C-' #+BEGIN_SRC

Because of ~/.emacs.d/elpa/org-plus-contrib-20160111/ (and prev version)
To fix it I edited org-plus-contrib-autoloads.el
I added this (from org.el) and it fixed both.
(defconst org-clock-line-re
  (concat "^[ \t]*" org-clock-string)
  "Matches a line with clock info.")

I'm not sure it's the best fix, but it works for me.

I hope others are not having problems too.

How should I find who to email about an error like this?