Activity finishes with
The operation is canceled because the backup window has closed
The activity has been canceled due to the closed backup window
Activity has failed due to backup window settings - e.g. you scheduled the backup during the "gray" period when backup is blocked or just before that period.
Re-configure schedule or edit options of the backup plan in Performance and backup window. Expand the the section with your product for instructions.
Even if scheduled backups are blocked, a backup can be started manually if needed.