Users may be unable to access Cowork in the Microsoft Copilot 365 User Interface (UI)
Operational Resolved
- Started
- Ended
- Affects
- Microsoft Copilot (Microsoft 365)
Timeline (UK time)
- Operational
A post-incident report has been published.
- Operational
A post-incident report has been published.
- Operational
Title: Users may be unable to access Cowork in the Microsoft Copilot 365 User Interface (UI) User impact: Users may have been unable to access Cowork in Copilot UI. More info: When attempting to access Cowork, users may have been redirected to Copilot Chat instead. Final status: We've confirmed the service has returned to healthy levels following our deployment to turn off the automated traffic management mechanisms, and we've confirmed with some previously impacted customers that impact is resolved. Scope of impact: This issue may have affected any user attempting to access Cowork. Start time: Thursday, November 5, 2026, at 4:30 PM UTC End time: Thursday, November 5, 2026, at 9:20 PM UTC Preliminary root cause: A recent deployment introduced an issue where additional calls were delivered to multiple API endpoints, which caused our automated traffic management mechanisms to reduce request traffic flow which resulted in impact. Next steps: - To help prevent similar impact in the future, we're further reviewing our deployment testing and validation processes and the scenarios which trigger our traffic management automations. We'll provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business days.
- Operational
We've completed our deployment to turn off the automated traffic management mechanisms that were reducing request traffic flow and we're reaching out to impacted customers to confirm remediation. This quick update is designed to give the latest information on this issue. Next update by: Thursday, November 5, 2026, at 10:30 PM UTC
- Operational
We're working on turning off the automated traffic management mechanisms that are reducing request traffic flow, which we anticipate will resolve impact. We'll aim to provide an estimated time to mitigation in our next scheduled update. This quick update is designed to give the latest information on this issue. Next update by: Thursday, November 5, 2026, at 10:30 PM UTC
- Operational
Title: Users may be unable to access Cowork in the Microsoft Copilot 365 User Interface (UI) User impact: Users may be unable to access Cowork in Copilot UI. More info: When attempting to access Cowork, users may be redirected to Copilot Chat instead. Current status: We've completed the roll back of the affecting change. However, we've received reports that impact persists. We believe that additional time is likely needed for our roll back to take effect and for stored cache to update for users to see relief. We're continuing to monitor while we investigate any potential additional actions that may be needed if impact does not remediate as expected. Scope of impact: This issue may affect any user attempting to access Cowork. Start time: Thursday, November 5, 2026, at 4:30 PM UTC Preliminary root cause: A recent deployment introduced an issue where additional calls are being delivered to multiple API endpoints, which caused our automated traffic management mechanisms to take action to reduce request traffic flow which resulted in impact. Next update by: Thursday, November 5, 2026, at 10:30 PM UTC
- Operational
Title: Users may be unable to access Cowork in the Microsoft Copilot 365 User Interface (UI) User impact: Users may be unable to access Cowork in Copilot UI. More info: When attempting to access Cowork, users may be redirected to Copilot Chat instead. Current status: We've identified a recent deployment introduced an issue where additional calls are being delivered to multiple API endpoints, which caused our automated traffic management mechanisms to take action to reduce request traffic flow which resulted in impact. We're developing a fix to roll back this change to remediate impact for all users. Scope of impact: This issue may affect any user attempting to access Cowork. Preliminary root cause: A recent deployment introduced an issue where additional calls are being delivered to multiple API endpoints, which caused our automated traffic management mechanisms to take action to reduce request traffic flow which resulted in impact. Next update by: Thursday, November 5, 2026, at 8:30 PM UTC
- Operational
Title: Users may be unable to access Cowork in the Microsoft Copilot 365 User Interface (UI) User impact: Users may be unable to access Cowork in Copilot UI. More info: When attempting to access Cowork, users may be redirected to Copilot Chat instead. Current status: We're investigating a potential issue with Copilot and checking for impact to your organization. We'll provide an update within 30 minutes.
Wording above is from Microsoft 365 service health. Original notice.