Microsoft 365 Outage Disrupts Teams, Outlook, and Copilot in Japan and China
On Thu, Dec 18, 2025, users in Japan and China experienced disruptions to Microsoft 365 services due to a critical routing issue affecting the company's infrastructure.
On Thu, Dec 18, 2025, users in Japan and China experienced disruptions to Microsoft 365 services due to a critical routing issue affecting the company's infrastructure.
The incident began at 12:00 AM UTC (8:00 AM JST), with users encountering login failures, application loading errors, and degraded performance across Microsoft 365 platforms, including Teams, Outlook, OneDrive, and Copilot.
The routing misconfiguration isolated healthy infrastructure components, preventing normal traffic distribution through the region’s data centers. Microsoft engineering teams responded promptly, and by 7:40 AM GMT+5:30, traffic was rebalanced across redundant systems to restore service availability.
The routing misconfiguration isolated healthy infrastructure components, preventing normal traffic distribution through the region’s data centers.
No data loss or security breaches were reported, and the incident was confirmed as an infrastructure issue rather than a cyberattack. However, the downtime significantly impacted business operations and remote work productivity for organizations relying on cloud-based collaboration tools.
Routing issues, often caused by Border Gateway Protocol (BGP) misconfigurations or peering problems, can lead to widespread effects. Microsoft has faced similar challenges previously, including an Azure outage in July affecting multiple services.
The incident highlights the importance of robust redundancy systems and rapid incident response protocols in maintaining enterprise cloud service reliability.
Based on reporting by GBHackers.