(hr=0x80004005, ec=1142)‎ when trying to migrate Exchange Server user

Question

Hi, I am trying to do migration from Exchange 2013 to Exchange 2016. I got the following error when trying to migrate user from 2013 to 2016 server.

Error: MigrationTransientException: MapiExceptionMdbOffline: Unable to get mailbox information. ‎(hr=0x80004005, ec=1142)‎ Diagnostic context: Lid: 49384 Lid: 51176 StoreEc: 0x476 Lid: 40680 StoreEc: 0x476 Lid: 43980 Lid: 58295 StoreEc: 0x476 Lid: 50103 Lid: 48311 StoreEc: 0x476 Lid: 43959 Lid: 60343 StoreEc: 0x476 --> MapiExceptionMdbOffline: Unable to get mailbox information. ‎(hr=0x80004005, ec=1142)‎ Diagnostic context: Lid: 49384 Lid: 51176 StoreEc: 0x476 Lid: 40680 StoreEc: 0x476 Lid: 43980 Lid: 58295 StoreEc: 0x476 Lid: 50103 Lid: 48311 StoreEc: 0x476 Lid: 43959 Lid: 60343 StoreEc: 0x476 This error suggests that the migration process is unable to access mailbox information due to the database being offline. I've attempted several troubleshooting steps, including checking the database status, ensuring Exchange services are running, verifying network connectivity, and reviewing permissions, but the issue persists. Also tried enabling MAPI over HTTP: Set-OrganizationConfig -MapiHttpEnabled $true

Answer 1

Hello @Jing Quan ,

The error you're seeing usually occurs when the migration process can't access mailbox information due to the database being offline. Based on your description, it seems like you've already checked the status of the database. If either the source or target database is in dismounted status, please mount it before retrying the migration.

Additionally, a simple solution to this problem is to restart the Exchange service. Have you tried restarting the Exchange service to see if it resolves the issue? Besides, we recommend using the PowerShell command Get-ServerHealth on both servers to check the running status of the Exchange servers and ensure they are operating properly.  

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Answer 2

Check my answer in this thread. Also, try to turn off the antivirus that might be blocking the transaction and later reconfiguring it.

Answer 3

May I know why do we need to mount? We would like to know does mounting affects the existing environment?