Error Message: You must provide a required property: Parameter Name: FederatedUser.SourceAnchor.
Possible cause:
This error occurs when you try to create a Microsoft 365 user directly in a federated domain. Once a domain is federated, users can no longer be directly added to Microsoft 365.
Troubleshooting Steps:
To create a Microsoft 365 user in a federated domain, create the user in Active Directory first, and then synchronize with Microsoft 365 using DirSync.