In a Microsoft Exchange Server 2010 hybrid environment, you try to on-board or off-board a mailbox through Exchange Online. If you use Exchange Server 2010 as the MRSProxy service, the migration ends unexpectedly and errors are reported.
When you on-board a mailbox to Exchange Online, the status is displayed as CompletedWithWarnings. This results in the mailbox existing in both locations.
When you off-board a mailbox from Exchange Online, the move status is displayed as Failed because the migration was unable to convert the target MailUser to a mailbox.
Additionally, the following error is logged in the move report:
Message: Warning: Unable to update Active Directory information for the source mailbox at the end of the move. Error details: An error occurred while updating a user object after the move operation. --> The type initializer for 'Microsoft.Exchange.Configuration.Tasks.TaskLogger' threw an exception. --> Access is denied.
This issue occurs because Windows does not let the MRSProxy service examine its own process. This raises an "Access Denied" exception.
To fix this issue, apply Update Rollup 17 for Exchange Server 2010 Service Pack 3.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.