TM1143347: Microsoft Teams Service Health Incident

[365 Service Alert]

Some users may be unable to access or open any Microsoft Office files within Microsoft Teams.                                                                                                                                                                                                               

Some users may be unable to access or open any Microsoft Office files within Microsoft Teams ID: TM1143347 Issue type: Incident Status Service Restored Impacted services Microsoft Teams Details Title: Some users were unable to access or open any Microsoft Office files within Microsoft Teams User impact: Users were unable to open or access any Microsoft Office files directly within Microsoft Teams. More info: Any attempt to open, view, or access Microsoft Office files within the Microsoft Teams service including team channels and tabs would have failed. While we focused on remediation, affected users were able to open impacted files by selecting the alternate "Open in desktop” or “Open in browser” options as a workaround. Impact was specific to Microsoft Office documents embedded into Microsoft Teams. Specifically, this affected products such as Microsoft Word, Microsoft Visio, Microsoft Excel, Microsoft PowerPoint, and Microsoft OneNote files. Final status: We’ve completed deployment to all affected environments and have validated through customer feedback and monitoring that the issue has been resolved. Scope of impact: Any user attempting to open embedded Microsoft Office files directly within Microsoft Teams was impacted. Start time: Wednesday, August 27, 2025, at 8:49 PM UTC End time: Thursday, August 28, 2025, at 4:07 AM UTC Preliminary root cause: A recent Content Delivery Network (CDN) path handling change contained a misconfiguration when fetching content, which inadvertently prevented users from opening or accessing embedded Microsoft files from Microsoft Teams directly. Next steps: - We're analyzing our CDN handling code changes and trends to better understand and prevent similar issues from occurring in the future. We'll provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business day. Is this message helpful? Did you find this email helpful? Yes No To customize what’s included in this email, who gets it, or to unsubscribe, set your Service health preferences. If you are receiving this email because your Admin added you as a recipient, please contact your Admin to unsubscribe. Privacy Statement Microsoft Corporation, One Microsoft Way, ​Redmond, WA 98052​