Note: You are currently viewing documentation for Moodle 3.0. Up-to-date documentation for the latest stable version of Moodle may be available here: error/moodle/confirmsesskeybad.


From MoodleDocs

This error occurs when you have an invalid unique session key. This is usually caused by hard-coding a Moodle URL into your course / site or by an attempt to circumvent the session key