Microsoft 365 Alert – Service Degradation – Microsoft Copilot (Microsoft 365) – Users couldn’t access Microsoft 365 Copilot in Excel – RESOLVED

Announcements Sharmista Mohanta

18/08/2026 01:58:00 PM

NHS.net Connect Reference: INC46912342

Microsoft Reference: CP1456911

Issue Status: RESOLVED

Issue Description: Users couldn’t access Microsoft Copilot in Excel.

More info: The Copilot pane may not have loaded when users selected the Copilot button. Users may have been able to access Copilot through the Excel desktop application.

This issue affects Copilot in both Excel on the desktop and the web versions.

Final Update: 18/08/2026 02:01:00 PM – Microsoft has determined that a recent change intended to update a supporting web component caused the Copilot pane to fail to load. They reverted the change to remediate the impact and confirmed in their testing environment that the issue is resolved.

Scope of impact: Your organisation was affected by this event, and any user couldn’t access Copilot in Excel on the desktop and on the web.

Root cause: A recent change intended to update a supporting web component caused the Copilot pane to fail to load.

Next steps: Microsoft is reviewing their validation and updating procedures to better detect and prevent issues like this prior to deployment in the future.