Students will be unable to view their Similarity Report and receive the error Your session has expired. You are not allowed to view this paper - M20: 27 when they are enrolled on the Moodle side, but not on the Turnitin side. This can happen if the student has been dropped or dropped themselves via the Turnitin website.
If any of your students are receiving this error message, please try to unenroll and then re-enroll them from your Moodle environment. If they still receive the error message after performing this action, please raise a support ticket with Turnitin Technical Support to manually re-add the users.