12/01/2024 08:40:00 AM
NHSMail Reference: INC40834673
Microsoft Reference: EX705975
Issue Status: RESOLVED
Issue Description: Admins may be unable to perform migration of Exchange Online mailboxes in some scenarios.
More info: Specifically, admins may be unable to perform tenant-to-tenant mailbox, on-premises to Exchange Online migrations, or cross-geo migrations. This impacts attempts in both the Exchange admin center and PowerShell.
Final Update: 17/01/2024 09:06:00 AM – Microsoft have applied the settings change to correct the null reference and reset the user migrations, after which, they confirmed that impact is completely remediated.
Scope of impact: Any admin attempting to perform tenant-to-tenant mailbox, on-premises to Exchange Online migrations, or cross-geo migrations may be affected.
Root cause: A null reference in data transformations is causing some failures in specific migration scenarios.
Next steps: Microsoft are reviewing the validation procedure for the recent change that introduced the offending null reference to identify methods of detecting similar issues before they cause impact in the future.