CodeCell.append_mime_type needed a default element.
@ -227,6 +227,7 @@ var IPython = (function (IPython) {
CodeCell.prototype.append_mime_type = function (json, element) {
element = element || this.element.find("div.output");
if (json.html !== undefined) {
this.append_html(json.html, element);
} else if (json.latex !== undefined) {