Event ID - 905

Event Id905
Description () Server registered: / (callback DLL , flags ).
Event InformationAccording to Microsoft :

This is an informational event typically associated with an Exchange store database or a Site Replication Service (SRS) database that dismounts with an error or cannot be mounted with an error.
Note "Server registered" always refers to Exchange Server and means that the Extensible Storage Engine (ESE) backup endpoints have been registered. The service referenced in the event can be the Microsoft Exchange Information Store service or the SRS.

The following are some specific causes and resolutions associated with ESEBackup Event 905:
1.The version of antivirus software being used had a problem that caused the database shutdown, and required an upgrade of the version, a downgrade of the version, or a fix. Check to determine whether this could be caused by the current state of the antivirus software installed on the server that is running Exchange. For information about troubleshooting this potential cause, contact your antivirus software vendor.
2.The incorrect restore file was selected for an online Exchange-aware restore. Rerun the restore process using the correct backup file.
3.Some of the log files used by the Exchange store database and the storage group had been removed and replaced. For information about troubleshooting Exchange transaction log file problems during data recovery, see Microsoft Knowledge Base article 812592 "How and when to manipulate Exchange transaction logs in disaster recovery" (http://go.microsoft.com/fwlink/?LinkId=3052&kbid=812592). If you still cannot restore your backup, examine the Application log for associated events that may help you determine the root cause of the Exchange store database failure or the SRS database failure.
Reference LinksEvent ID:905 Of Source ID:ESE BACKUP

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