At least one root path cannot be found in the backup file (4320857)

The error "At least one root path cannot be found in the backup file" is displayed when a user tries to preview objects in a Security Explorer backup archive file. All the backup archive files are only 1KB in size indicating that the backups are not completing successfully, although the Windows Task Scheduler showed that the Schedule backup task ran and completing successfully.

Manually executing the backup using SXPBackup.exe from the command line, with the same command from the backup schedule with the mapped drive (the one that failed), it executes successfully.