[Error Code] 0x80040109 or Fail:While stamping the message [Explanation] 
This problem does not indicate that messages failed to migrate, only that the tool couldn't save the fact that they were migrated. The only negative consequence is that if the migration is re-run at a later time with 'Only New Data' checked, the tool will attempt to migrate these messages again since it doesn't have a record of their being migrated previously. This will not cause message duplication, but may lead to calendar or contacts duplicates. Another process (such as anti-virus, desktop search, or backup software) is accessing the migration tool's database file during the migration. This interrupts the tool's ability to save the state of that message. We recommend finding and disabling the software causing this issue for the duration of your migration.