Account Migration failed with the below error:
Some of attributes of the "User@Domain.com" object cannot be completely transferred during this session. Reason: Unable to update the specified properties for on-premises mastered Directory Sync objects or objects currently undergoing migration. Re-run the migration task to complete attribute transferring.
The above error is encountered when the object exists in both source and target, and you try to use Migrate Accounts.
Resolution:
When to use the Match / Map option
If the Object exists in Both the Source and Target tenants, you will need to match / map the source account to target account.
If the default matching rules provided in the 'match accounts' task are not sufficient for your environment, then you can create a “manual match” by using the 'Map from File' option in ODM, described in this KB article: How to map accounts from a file (266967)
When to Use Migrate Accounts
If the Object only exists in the Source Tenant, then you would need use the 'Migrate Accounts' task to create a corresponding object in the Target tenant.
