Note: You are currently viewing documentation for Moodle 3.1. Up-to-date documentation for the latest stable version of Moodle is probably available here: error/moodle/invalidcourse.
The ID number of the course is incorrect in the URL or in the form you are submitting.
This is most likely because you have an invalid, malformed, or truncated URL. It is also possible that you have clicked a link to a course that has been deleted.