If you set up a CA (Certification Authority) on Windows Server 2003, using NTBackup to perform a system state backup causes a event similar to the following to be logged in the event log:

Event Type: Error
Event Source: ESENT
Event Category: Logging/Recovery
Event ID: 215
Date: MM/DD/YYYY
Time: HH:MM
User: N/A
Computer:
Description: certsrv.exe (1368) The backup has been stopped because it was halted by the client or the connection with the client failed.

This behavior occurs because NTBackup incorrectly refers to the backup information to obtain the file list of objects backed up, instead of referring to the backup media.

You can safely ignore this event as no problem actually occurred during the backup process.