To view your cancelled classes, please see How to view your cancelled classes.
To un-cancel a class, click the desired class on your calendar or in the cancelled classes report, then click 'Options - Un-cancel'.
Please note that un-cancelling a class won't reinstate attendees, so if they need to be booked back in, this will need to be done manually.
You can find the attendees by viewing the activity feed in the class, as seen below:
