Using emacs 26.1 (in case it matters). Loading is failing at:
(defconst org-element--current-element-re (rx (or (group-n 1 (regexp org-element--latex-begin-environment-nogroup))rx is a macro, and so org-element* is not being evaluated. It's complaining that the argument to regexp is not a stringp.
Does the rx argument need a backquote? org-element-clock-line-re uses rx-to-string with a backquote?
(rx `(or (group-n 1 (regexp ,org-element--... -Justin
