[Plugin: CKEditor For WordPress] Editor fails to load

Hi,

I got a fresh install of wp. Now ckeditor in admin backend works fine. But it doesn’t as a user:
file: ckeditor/ckeditor.js?ver=3.0.1:6

Uncaught TypeError: Object function each(iterator, context) {
    var index = 0;
    try {
      this._each(function(value) {
        iterator.call(context, value, index++);
      });
    } catch (e) {
      if (e != $break) throw e;
    }
    return this;
  } has no method 'indexOf'

Is this related to caching perhaps?

https://www.ads-software.com/extend/plugins/ckeditor-for-wordpress/