Microsoft 365 Alert – Service Degradation – Microsoft Copilot (Microsoft 365) – Users couldn’t access Copilot Agent Builder in Microsoft Teams or Exchange Online – RESOLVED

12/08/2026 09:00:00 AM

NHS.net Connect Reference: INC46907058

Microsoft Reference: CP1453059

Issue Status: RESOLVED

Issue Description: Users can’t access the Microsoft 365 Copilot Agent Builder in Microsoft Teams or Exchange Online.

Final Update: 12/08/2026 09:00:00 AM – Microsoft determined that a recent update to the Copilot Agent Builder was configured to match a specific configuration of Microsoft Teams and Exchange Online. Microsoft Teams and Exchange Online weren’t updated with this configuration, causing a mismatch with the Agent Build that resulted in impact. They have reverted the recent update and completed the deployment of the previous healthy version, remediating impact.

Scope of impact: Your organization was affected by this event, and any user attempting to access the Copilot Agent Builder in Microsoft Teams or Exchange Online was impacted.

Root cause: A configuration mismatch between a recent Copilot Agent build update, Microsoft Teams, and Exchange Online resulted in impact.

Next steps: Microsoft is reviewing and improving our feature update validation and synchronization process to prevent future misconfigurations.