Troubleshooting
The reviewer's deadline has passed
Giving more time, cancelling the invitation or inviting another reviewer when a reviewer did not respond in time or is late with the review.
The row of an invitation whose deadline has passed carries the Overdue label. What you do depends on the status of the invitation.
The reviewer did not respond to the invitation
An invitation whose response period has ended closes automatically shortly afterwards, and its status changes to Expired. You get a notification too. You can invite the same reviewer again with Invite again in the Invitation actions menu of the invitation, or invite another reviewer.
The reviewer is late with the review
For an accepted invitation, reminders go to the reviewer at regular intervals once the review deadline has passed. To give the reviewer more time, select Change deadlines in the Invitation actions menu of the invitation and enter a new Review due date. The reminder counter is reset.
If the reviewer is not going to send a review, cancel the invitation with Cancel invitation and invite another reviewer.
The actions are described in Tracking Invitations and Reviews. When reminders go out is described in Reviewer Deadlines and Reminders.