When a Turnitin assignment is created within a Learning Management System (LMS), a Turnitin class is created for the course the assignment sits in if one does not already exist. This Turnitin class has a default end date that is typically twelve months from the creation date or on the day of the latest post date for Turnitin assignments in that class, whichever is the latest. Once this end date is reached, the class expires. This means that any submissions in this class become read-only.
Instructors will still be able to view the Similarity Report and any grades, comments, or rubrics attached, but it will not be possible to make any modifications until the class is reactivated. Instructors may be able to extend the class by adding a new Turnitin assignment to the course within the LMS. If no new Turnitin assignments can be added, Turnitin Technical Support may be able to assist with reactivating the class on the Turnitin side so that it becomes active again.
Note: Turnitin classes have a maximum term limit of five years and cannot be extended beyond this. If the Turnitin class associated with a course has reached its term limit, instructors will need to create a new course.
If you are using Moodle as your LMS, please refer to the following article for reactivating an expired Turnitin class: https://helpcenter.turnitin.com/hc/en-us/articles/27975580497293-How-can-I-reactivate-an-expired-class-in-Moodle