I wonder if something in the new export backend system has broken inserting export option templates? Choosing anything but "default" as the backend gives me this backtrace, in this case html. The offending functions seem to have no definition (compiler macros?) so I couldn't poke further, but it looks like a symbol's being given to something that expects the new struct-based backend.
Debugger entered--Lisp error: (wrong-type-argument arrayp html) org-export-backend-name(html) (org-export-get-all-options (org-export-backend-name backend)) (cond ((eq backend (quote default)) org-export-options-alist) ((org-export-backend-p backend) (org-export-get-all-options backend)) (t (org-export-get-all-options (org-export-backend-name backend)))) org-export-insert-default-template(nil nil) org-export-dispatch(nil) call-interactively(org-export-dispatch nil nil)