Problem
You are attempting to migrate Exchange 2007 or 2010 mailboxes to a new Exchange 2013 environment but notice a few mailboxes have failed with the following error message:
Data migrated:
Migration rate:
Error: MigrationPermanentException: Active Directory property 'homeMDB' is not writeable on recipient 'domain.local/IT Department/Gary Black'. --> Active Directory property 'homeMDB' is not writeable on recipient 'domain.local/IT Department/Gary Black'.
Solution
One of the reasons why this error would be thrown is if the user object’s security permissions have inheritance disabled:
Enabling inheritance for the user object and re-initiating the migration of the problematic mailbox will correct the issue: