OneDrive Migration task failed due to provisioning error “the web site does not support SharePoint Online credentials. The response status code is 'Unauthorized' or ‘Forbidden’”. (4382751)

During OneDrive Migration, if the target OneDrive is not provisioned, the automated provisioning process may fail with an authorization error. This behavior has been observed during recent testing and has been confirmed in limited production scenarios. 

Current observed behavior: 

• Occurs only during first‑time provisioning
• Returns HTTP 401 Unauthorized
• No retry succeeds until OneDrive is provisioned through an alternative method
• No data loss or partial site creation observed 

Root Cause (Current Understanding) 

Microsoft has been introducing changes to authentication and service boundary enforcement across M365. While SharePoint APIs continues to function as expected for general operations, OneDrive provisioning within On Demand Migration for OneDrive Migration Tasks now enforces additional authorization requirements. 

As a result: 

• Authentication flows that previously succeeded for OneDrive provisioning may no longer be sufficient
• Failure occurs specifically during the initial OneDrive provisioning process, not during subsequent migration, access or management 

We are actively working with Microsoft to understand the scope and long-term expectations for this behavior.  

What this Means for You  

• If the target OneDrive is already provisioned, there is no impact.
• If the target OneDrive has not been provisioned, the migration task may not complete.
• Existing data, access, and OneDrive functionality are not impacted. At this time (8th April 2026), we have not seen widespread customer impact, which suggests that most target environments already have OneDrive provisioned for active users or that the change causing this impact has not been completely rolled out by Microsoft.  

If OneDrive provisioning is required as part of the migration process, Microsoft provides a supported administrative workaround using PowerShell. 

Supported Workaround 

• Use SharePoint Online / OneDrive administrative PowerShell commands to provision OneDrives on the target prior to migrating with On Demand Migration.
• More information can be found here: https://learn.microsoft.com/en-us/sharepoint/pre-provision-accounts 

Operational Guidance  

• For environments onboarding new users, we recommend validating OneDrive availability early in the lifecycle (e.g. as part of post-provisioning checks).
• For Tenants with existing users, no action is required unless the user has never accessed OneDrive before.