Microsoft 365 Alert – Service Degradation – Microsoft Defender XDR – Some users may not receive Sandbox Analysis details in Microsoft Defender for Office 365 – RESOLVED

Announcements Arpan Das

12/02/2026 08:55:00 AM

NHSmail Reference: INC46748246

Microsoft Reference: DZ1230830

Issue Status: RESOLVED

Issue Description: Users may have not received Sandbox Analysis details in Microsoft Defender for Office 365.

Final Update: 12/02/2026 08:56:00 AM – Microsoft’s has completed the deployment of this fix to all affected environments and have confirmed that this action has restored service.

Scope of impact: This event may have impacted any user attempting to view Sandbox Analysis details in Microsoft Defender for Office 365.

Root cause: Authentication components were upgraded in the service, which led to a regression after the Operating System (OS) underwent a recent update.

Next Steps: Microsoft are reviewing the responsible update to the authentication components to better understand what led to the error that resulted in impact and prevent similar future occurrences.