Stata code blocks no longer execute

After not using it for a while, I just tried using ob-stata again, and found that Stata code blocks no longer execute! I updated ob-stata.el, but with no effect. The error message is below:

Debugger entered--Lisp error: (void-function stata) (stata) (set-buffer (stata)) (progn (if (get-buffer session) (progn (set-buffer session))) (require (quote ess)) (set-buffer (stata)) (rename-buffer (if (bufferp session) (buffer-name session) (if (stringp session) session (buffer-name)))) (current-buffer)) (unwind-protect (progn (if (get-buffer session) (progn (set-buffer session))) (require (quote ess)) (set-buffer (stata)) (rename-buffer (if (bufferp session) (buffer-name session) (if (stringp session) session (buffer-name)))) (current-buffer)) (set-window-configuration wconfig)) (let ((wconfig (current-window-configuration))) (unwind-protect (progn (if (get-buffer session) (progn (set-buffer session))) (require (quote ess)) (set-buffer (stata)) (rename-buffer (if (bufferp session) (buffer-name session) (if (stringp session) session (buffer-name)))) (current-buffer)) (set-window-configuration wconfig))) (if (org-babel-comint-buffer-livep session) session (let ((wconfig (current-window-configuration))) (unwind-protect (progn (if (get-buffer session) (progn (set-buffer session))) (require (quote ess)) (set-buffer (stata)) (rename-buffer (if (bufferp session) (buffer-name session) (if (stringp session) session (buffer-name)))) (current-buffer)) (set-window-configuration wconfig)))) (let ((session (or session "*stata*")) (ess-ask-for-ess-directory (and (boundp (quote ess-ask-for-ess-directory)) ess-ask-for-ess-directory (not (cdr (assq :dir params)))))) (if (org-babel-comint-buffer-livep session) session (let ((wconfig (current-window-configuration))) (unwind-protect (progn (if (get-buffer session) (progn (set-buffer session))) (require (quote ess)) (set-buffer (stata)) (rename-buffer (if (bufferp session) (buffer-name session) (if ... session ...))) (current-buffer)) (set-window-configuration wconfig))))) (if (string= session "none") nil (let ((session (or session "*stata*")) (ess-ask-for-ess-directory (and (boundp (quote ess-ask-for-ess-directory)) ess-ask-for-ess-directory (not (cdr (assq :dir params)))))) (if (org-babel-comint-buffer-livep session) session (let ((wconfig (current-window-configuration))) (unwind-protect (progn (if (get-buffer session) (progn ...)) (require (quote ess)) (set-buffer (stata)) (rename-buffer (if ... ... ...)) (current-buffer)) (set-window-configuration wconfig)))))) org-babel-stata-initiate-session(nil ((:colname-names) (:rowname-names) (:result-params "replace") (:result-type . value) (:results . "replace") (:exports . "code") (:cache . "no") (:noweb . "no") (:hlines . "no") (:tangle . "no") (:session))) (let* ((result-params (cdr (assq :result-params params))) (result-type (cdr (assq :result-type params))) (session (org-babel-stata-initiate-session (cdr (assq :session params)) params)) (graphics-file (and (member "graphics" (assq :result-params params)) (org-babel-graphical-output-file params))) (colnames-p (if graphics-file nil (cdr (assq :colnames params)))) (rownames-p (if graphics-file nil (cdr (assq :rownames params)))) (full-body (org-babel-expand-body:stata body params graphics-file)) (result (org-babel-stata-evaluate session full-body result-type result-params (or (equal "yes" colnames-p) (org-babel-pick-name (cdr (assq :colname-names params)) colnames-p)) (or (equal "yes" rownames-p) (org-babel-pick-name (cdr (assq :rowname-names params)) rownames-p))))) (if graphics-file nil result)) (save-excursion (let* ((result-params (cdr (assq :result-params params))) (result-type (cdr (assq :result-type params))) (session (org-babel-stata-initiate-session (cdr (assq :session params)) params)) (graphics-file (and (member "graphics" (assq :result-params params)) (org-babel-graphical-output-file params))) (colnames-p (if graphics-file nil (cdr (assq :colnames params)))) (rownames-p (if graphics-file nil (cdr (assq :rownames params)))) (full-body (org-babel-expand-body:stata body params graphics-file)) (result (org-babel-stata-evaluate session full-body result-type result-params (or (equal "yes" colnames-p) (org-babel-pick-name (cdr ...) colnames-p)) (or (equal "yes" rownames-p) (org-babel-pick-name (cdr ...) rownames-p))))) (if graphics-file nil result))) org-babel-execute:stata("webuse auto \nreg price mpg ///\n weight" ((:colname-names) (:rowname-names) (:result-params "replace") (:result-type . value) (:results . "replace") (:exports . "code") (:cache . "no") (:noweb . "no") (:hlines . "no") (:tangle . "no") (:session))) org-babel-execute-src-block(nil ("stata" "webuse auto \nreg price mpg ///\n weight" ((:colname-names) (:rowname-names) (:result-params "replace") (:result-type . value) (:results . "replace") (:exports . "code") (:session) (:tangle . "no") (:hlines . "no") (:noweb . "no") (:cache . "no")) "" nil 1 "(ref:%s)")) org-ctrl-c-ctrl-c(nil) funcall-interactively(org-ctrl-c-ctrl-c nil) call-interactively(org-ctrl-c-ctrl-c nil nil) command-execute(org-ctrl-c-ctrl-c)