Occasionally a class may accidentally be archived and you may think it is lost. You can find archived classes and reactivate them without losing any data.
To view archived classes, click on the Archived Classes button on the upper left corner of the Home screen.
Click on the clock icon in the lower left corner of the tile for the class you wish to reactivate.
Click yes to confirm the reactivation.
Go back to the My Classes tab and the class will now be listed and active.