Microsoft 365 Alert – Service Degradation – Microsoft Copilot (Microsoft 365) – Users may intermittently receive blank responses from Analyst Agent in Microsoft Copilot – RESOLVED

22/05/2026 08:46:00 AM

NHSmail Reference: INC46833441

Microsoft Reference: CP1318025

Issue Status: RESOLVED

Issue Description: Users may intermittently receive blank responses from Analyst Agent in Microsoft Copilot.

More info: Affected users can bypass impact by creating a new chat window within the Analyst Agent in Microsoft Copilot.

Final Update: 28/05/2026 09:33:00 AM – Microsoft has completed safely disabling the offending OneDrive file and link feature within the affected infrastructure, and they have validated with internal testing that the issue is resolved.

Scope of impact: Some admins relying on security telemetry reporting in Microsoft Defender for Endpoint may be impacted. This information may be updated as our investigation continues.

Root cause: This event may impact any user utilizing the Analyst Agent in Microsoft Copilot, and any user might intermittently receive blank responses. This information may be updated as our investigation continues.

Next Steps: Microsoft are further reviewing the recent change to understand how the code regression was introduced, and to understand what prevented it from being detected in their update testing and validation procedures, which will allow them to prevent similar issues in future changes.