When students try to log in to a course, they get the message "You cannot enrol yourself into this course."
Check the settings for the Self-enrolment method:
- In the course, select "Participants", then "Enrolment methods"
- Look in the settings for the method called "Self-enrolment (Student)".
Specifically check to make sure that the start and end dates are not enabled and you're now outside of the date range. If so, disable or change the date. The preferable solution is to disable this setting.