Couldn't find database error

Question

I’m trying to migrate a mailbox from Exchange 2013 to Exchange 2019, but the process keeps failing. The error I’m getting says “Couldn’t find database”, and it’s referencing a database that has already been deleted from the environment. Has anyone run into this problem before or know what might be causing it?

Answer 1

Hi @Johnny Blaze

Thank you for posting your question in the Q&A Forum. 

You may see this error during a mailbox migration if an old reference still exists in Active Directory. 

The error “Couldn’t find database” occurs when a mailbox move request or an AD object still points to a database that has already been deleted. Even though the database is removed from Exchange, its reference may still exist in AD, which can cause the migration to fail. 

To help resolve the issue, you can try running the following PowerShell command on a domain controller or a machine that has Active Directory tools installed: 

dsquery * forestroot -attr * -limit 0 > C:\temp\result.txt   

Note: Search result.txt for the name of the missing database to identify affected AD objects. 

Next, open the exported file and look for the name of the missing database to find the affected Active Directory objects. Once you’ve identified them, open Active Directory Users and Computers (make sure Advanced Features is enabled), locate the corresponding objects, switch to the Attribute Editor tab, and clear the values for the homeMDB and homeMTA attributes. 

Note: Make sure you have the appropriate permissions and have backed up AD before making any changes. 

It’s also recommended to verify that arbitration mailboxes are hosted on valid databases. You can do this by running: 

Set-ADServerSettings -ViewEntireForest $true; Get-Mailbox -Arbitration | Format-Table Name, ServerName, Database, AdminDisplayVersion 

Finally, retry the mailbox migration using the following cmdlet: 

New-MoveRequest -Identity '******@contoso.com' -TargetDatabase "YourTargetDatabase" 

Note: Replace the placeholders with the actual user and database names. 

For more information on monitoring or troubleshooting mailbox moves, you may refer to the official Microsoft documentation: Get-MoveRequest (ExchangePowerShell) | Microsoft Learn 

This approach is a standard and effective fix for stale database references during Exchange mailbox migrations. 

If you need further guidance or assistance with any of the steps, please feel free to reach out. 

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