Microsoft 365 Alert – Service Degradation – Microsoft 365 Copilot Chat – Users may be unable to access Copilot Voice in Microsoft 365 Copilot Chat or conduct voice conversations – RESOLVED

Announcements Shagufta Naaz

18/05/2026 09:23:00 AM

NHSmail Reference: INC46828770

Microsoft Reference: CW1314072

Issue Status: RESOLVED

Issue Description: Users may be unable to access Copilot Voice in Microsoft 365 Copilot Chat or conduct voice conversations.

More info: Affected users may be unable to launch the Microsoft Teams desktop client due to failures during character encoding conversion.

Final Update: 18/05/2026 09:23:00 AM –Microsoft has confirmed that a routing conflict during a recent update caused the system to incorrectly match certain requests, causing impact. They have developed and deployed a fix to the offending change. After a period of monitoring the service health telemetry, they have confirmed that the errors associated with impact are resolved and the issue is remediated.

Scope of impact: This issue may have prevented any user from accessing Copilot Voice in Copilot Chat or conducting voice conversations. This information may be updated as our investigation continues.

Root cause: A routing conflict introduced during a recent update caused the system to incorrectly match certain requests that included an API version identifier, resulting in the impact.

Next steps : Microsoft are reviewing why a routing conflict introduced during a recent update cause the system to incorrectly match requests, to assist us in preventing similar future impact.