i see this same behavior. to me, (org-babel-R-assign-elisp) seems to be the problem, but it hasn't changed any time recently. (nor, if my =git blame= is done correctly, has anything else in ob-R.el.)
i don't understand how (org-babel-R-assign-elisp) thinks. it seems to assign =max= and =min= assuming that =value= is a list of (at least one) list(s). this *might* be a fix. but, i don't have a lot of confidence it will not have bad side effects for other cases. (though i tested it with a simple list, and a simple table with more than one row, and a list of two lists, the first of length 3, the second of length 2.): ---- modified lisp/ob-R.el @@ -241,7 +241,7 @@ This function is called by `org-babel-execute-src-block'." (defun org-babel-R-assign-elisp (name value colnames-p rownames-p) "Construct R code assigning the elisp VALUE to a variable named NAME." (if (listp value) - (let* ((lengths (mapcar 'length (cl-remove-if-not 'sequencep value))) + (let* ((lengths (mapcar 'length (cl-remove-if-not 'listp value))) (max (if lengths (apply 'max lengths) 0)) (min (if lengths (apply 'min lengths) 0))) ;; Ensure VALUE has an orgtbl structure (depth of at least 2). ----