Hi, I have been looking in registry keys on a clients server (checking the set database size) and have foundan oddapparent error forone database. Exchange 2007, no SP's as yet.In this key path hklm:\System\CurrentControlSet\Services\MSExchangeIS\<servername>\<Private-GUID>MdbMountError : -1023Another database on the same server has0 for the value on the MdbMountError.There do not apear to be any obvious issues on the server.Goolgling reveals very little, does nayone know anything about this?Thanks, regards PEter.

Hi Peter, I do not found many information regarding the registry key MdbMountError. Nevertheless, based on my local test, if any error is encountered when mounting database, the error is record in the registry key. If the database is able to be mounted later, the MdbMountError registry key should be set to 0 again. Looks like for some reason the registry key is not set correctly if the database is mounted with no problem currently. Nevertheless, as the Mailbox Server works correct currently, I think that you can ignore the issue. Mike Shen TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com