Active and archived invitations
So that the list of all invitations doesn't get too long and hard to navigate, we move every invitation whose end date has passed into its own category called Archived invitations. Right above the list of your invitations you'll find the option to show Active or Archived invitations.
If you want an invitation to move from Archived back to Active, you can simply edit the End date to a future date, and it will then appear in the list of Active invitations. You do this under general information.