On an Exchange Server 2007 an error may occur when attempting to use the Mailbox Move Wizard or the Move-Mailbox cmdlet to move a user mailbox.

Retrieving the COM class factory for component with CLSID {08D1AA55-704E-4397-AB29-55D2A3972BCB} failed due to the following error: 8007007e.

COM Class Factory Error 8007007E Moving Mailboxes in Exchange Server 2007

The Application event log will contain a corresponding log entry.

Event Type: Error
Event Source: MSExchange Common
Event Category: General
Event ID: 4999
Date: 21/07/2010
Time: 4:07:01 PM
User: N/A
Computer: SERVER
Watson report about to be sent to dw20.exe for process id: 5312, with parameters: E12, c-RTL-AMD64, 08.02.0176.002, mmc, M.E.Management, M.E.M.R.MoveMailbox.CreateMigrationComObject, S.IO.FileNotFoundException, 911d, 08.02.0176.002. ErrorReportingEnabled: False

Notice the S.IO.FileNotFoundException part of the event log entry.  This is a clue that there is a file missing.  The question is, which file?

The answer is in the CLSID from the error message.  By searching the registry for the CLSID we find the following entry.

COM Class Factory Error 8007007E Moving Mailboxes in Exchange Server 2007

The CLSID corresponds with the migbase.dll file in the Exchange Server binaries folder.  On the server that was having this error the file was missing entirely, for reasons unknown.

There are three ways to recover the file:

  • Restoring from backup (may be difficult if you don’t know when it went missing)
  • Copying from another server (make sure you choose a server of the same Service Pack and Update Rollup version)
  • Applying/re-applying the latest Service Pack

About the Author

Paul Cunningham

Paul is a former Microsoft MVP for Office Apps and Services. He works as a consultant, writer, and trainer specializing in Office 365 and Exchange Server. Paul no longer writes for Practical365.com.

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