Users in Japan and China are experiencing access and sign‑in issues with Microsoft 365 and Microsoft Copilot

Title: Users in Japan and China are experiencing access and sign‑in issues with Microsoft 365 and Microsoft Copilot

User impact: Users in Japan and China are experiencing access and sign‑in issues with Microsoft 365 and Microsoft Copilot.

Current status: The service health remains stable and users should now be experiencing improved access to Microsoft 365 and Copilot services. We're continuing to monitor for an extended period to ensure complete service recovery.


Scope of impact: Your organization may be affected by this event, and some users in Japan, China, and Malaysia who are attempting to access Microsoft 365 services including Copilot may be impacted. This information may be updated as our investigation continues.

Start time: Thursday, December 18, 2025, at 12:00 AM UTC

Preliminary root cause: A traffic routing issue caused infrastructure in Japan to become unhealthy, which ultimately blocked users from successfully connecting to Microsoft 365 and Copilot services.

Next update by: Thursday, December 18, 2025, at 4:00 AM UTC

Current status: We've confirmed that service health has largely recovered following our mitigative actions. We’ll maintain elevated monitoring to confirm full recovery.

This quick update is designed to give the latest information on this issue.

Title: Users in Japan and China are experiencing access and sign‑in issues with Microsoft 365 and Microsoft Copilot

User impact: Users in Japan and China are experiencing access and sign‑in issues with Microsoft 365 and Microsoft Copilot.

Current status: We’ve confirmed that service telemetry is showing a positive recovery following the applied mitigation. We’ll continue to monitor closely to confirm complete restoration.

Scope of impact: Your organization may be affected by this event, and some users in Japan, China, and Malaysia who are attempting to access Microsoft 365 services including Copilot may be impacted. This information may be updated as our investigation continues.

Start time: Thursday, December 18, 2025, at 12:00 AM UTC

Preliminary root cause: A traffic routing issue caused infrastructure in Japan to become unhealthy, which ultimately blocked users from successfully connecting to Microsoft 365 and Copilot services.

Next update by: Thursday, December 18, 2025, at 3:00 AM UTC

Current status: We’ve identified that a portion of service infrastructure, supporting user traffic in Japan, became impacted at approximately 12:00 AM UTC due to a routing issue. We’ve taken mitigating actions to rebalance the traffic across healthy infrastructure to restore availability. We're working to confirm full recovery.

This quick update is designed to give the latest information on this issue.

Title: Users in the Japan region are currently experiencing access and sign‑in issues with Microsoft 365 and Microsoft Copilot

User impact: Users in the Japan region are currently experiencing access and sign‑in issues with Microsoft 365 and Microsoft Copilot.

Current status: We’re actively reviewing service telemetry to identify the underlying cause of the issue and determine appropriate mitigation actions.

Scope of impact: Your organization may be affected by this event, and some users attempting to access Microsoft 365 services including Copilot may be impacted.

Next update by: Thursday, December 18, 2025, at 2:00 AM UTC

Title: Investigating user reports of Microsoft 365 Services and Microsoft Copilot issues in Japan

User impact: We don't have detail on impact yet. We're seeing an increase in user reported issues above our alerting threshold.

Current status: We are reviewing service telemetry and available information to determine if there is an issue happening and we'll update this message shortly with our latest findings.