Microsoft 365 Alert – Service Degradation – Microsoft Defender XDR – Some users may see an unknown status for submissions in Microsoft Defender for Office 365 – RESOLVED

10/04/2025 09:15:00 AM

NHSmail Reference: INC46502070

Microsoft Reference: DZ1052047

Issue Status: RESOLVED

Issue Description: Some users may see an unknown status for submissions in Microsoft Defender for Office 365.

Final Update: 18/04/2025 08:55:00 AM – Microsoft have reconfirmed that the completion of their fix deployment successfully remediated impact for all new submissions.

Scope of impact: Impact may occur for some users that attempt to make submissions in Microsoft Defender for Office 365.

Root cause: A recent service change to update a portion of infrastructure that supports submissions in Microsoft Defender for Office 365 resulted in impact.

Next steps: Microsoft are reviewing their change testing and validation procedures to identify opportunities to improve impact detection and prevent similar future occurrences.