Microsoft Teams Experiences Service Degradation, Impacting Users in Europe and the US
Microsoft Teams users in Europe and the United States experienced service disruptions on , with reports of delays and access issues. The company confirmed the outage and stated it was working to resolve the problems, which affected the ability to send and receive chat messages containing inline media, join meetings, and manage Copilot Studio agents.
According to Microsoft, the initial incident, tracked under ID TM1233974, specifically impacted users attempting to send and receive chat messages with images, code snippets, and videos. Users also reported trouble joining meetings through the desktop and web apps, and difficulties signing in. A separate issue (TM1231009) prevented some users from joining meetings directly from chat conversations, while another (TM1218513) blocked others from adding or updating Copilot Studio agents within Teams.
The root cause of the primary disruption was traced to a subsection of Microsoft’s service infrastructure related to caching, which fell below acceptable performance thresholds. Microsoft engineers identified the issue through telemetry data and implemented a fix by reverting a recent configuration change to the last known healthy version. The company confirmed impact remediation after monitoring service telemetry for a period of time.
While Microsoft did not disclose the exact number of users affected, the scale of the platform – with over 320 million monthly active users – suggests a potentially widespread impact. The incident was classified as a “service degradation,” indicating a significant disruption to normal functionality.
This isn’t the first time Microsoft’s services have faced widespread outages recently. In , a similar outage affected multiple Microsoft 365 services, including Outlook and Teams, impacting over 15,000 users. That incident was attributed to issues with the service infrastructure in North America. A brief outage also occurred on , which investigators blamed on a third-party networking issue.
The October 2025 outage, which also impacted Teams, extended beyond the core collaboration platform to include Exchange Online and caused issues with Multi-Factor Authentication (MFA) for users relying on Microsoft Entra single sign-on (SSO). These recurring incidents raise questions about the resilience of Microsoft’s cloud infrastructure and the potential for cascading failures across its suite of services.
Caching infrastructure plays a critical role in the performance of large-scale applications like Microsoft Teams. By storing frequently accessed data closer to users, caching reduces latency and improves responsiveness. When caching systems experience issues, as was the case here, it can lead to significant performance degradation and service disruptions. Reverting to a previous configuration, as Microsoft did, is a common troubleshooting step to restore functionality quickly, but it highlights the importance of robust testing and monitoring of configuration changes.
The recent spate of outages affecting major tech platforms – including X (formerly Twitter) and OpenAI – underscores the increasing complexity of modern cloud infrastructure and the challenges of maintaining high availability. As these platforms become increasingly integral to daily operations for individuals and businesses, the impact of outages extends far beyond simple inconvenience.
Update : Microsoft has confirmed that the Teams delays and access issues have been addressed. The company stated that reverting the configuration change to the last healthy version resolved the problem, and service telemetry monitoring confirmed the remediation.
