Some users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page

Title: Some users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page User impact: Users may have been unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page. More info: Users couldn't access Microsoft Copilot through application-based Microsoft Copilot services. This included, but was not limited to: - Microsoft Copilot desktop app - Copilot in Microsoft Teams - Copilot in Office apps Users may have been able to leverage https://m365.cloud.microsoft/search, and should been able to sign in using this page. Once signed in, users could access Office.com. Final status: We monitored our telemetry after implementing our configuration changes and confirmed that the impact was remediated. Scope of impact: Impact was specific to users who were attempting to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page. Start time: Thursday, April 2, 2026, at 8:40 PM UTC End time: Friday, April 3, 2026, at 12:55 AM UTC Root cause: The infrastructure that supports access to Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign-in page was not processing traffic efficiently, which prevented some users from accessing the service pages. Next steps: - We're reviewing performance data and trends on the affected infrastructure to help develop improved preventative measures to avoid similar impact in the future. This is the final update for the event.

Title: Some users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page User impact: Users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page. More info: Users can access Microsoft Copilot through application-based Microsoft Copilot services. This includes, but is not limited to: - Microsoft Copilot desktop app - Copilot in Microsoft Teams - Copilot in Office apps User may be able to leverage https://m365.cloud.microsoft/search, and should be able to sign in using this page. Once signed in, users can access Office.com. Current status: Since making our configuration changes, we've seen some recovery of the service infrastructure. We're evaluating whether the implementation of additional optimizations are needed for full recovery. Scope of impact: Impact is specific to users who are attempting to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page. Start time: Thursday, April 2, 2026, at 8:40 PM UTC Root cause: The infrastructure that supports access to Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign-in page is not processing traffic efficiently, preventing some users from accessing the service pages. Next update by: Friday, April 3, 2026, at 2:30 AM UTC

Title: Some users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page User impact: Users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page. More info: Users can access Microsoft Copilot through application-based Microsoft Copilot services. This includes, but is not limited to: - Microsoft Copilot desktop app - Copilot in Microsoft Teams - Copilot in Office apps User may be able to leverage https://m365.cloud.microsoft/search, and should be able to sign in using this page. Once signed in, users can access Office.com. Current status: We've identified that a section of service infrastructure is not processing traffic efficiently. We're making configuration changes to remediate impact. Scope of impact: Impact is specific to some users who are served through the affected infrastructure. Root cause: The infrastructure that supports access to the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign-in page is not processing traffic efficiently, preventing some users from accessing the service pages. Next update by: Friday, April 3, 2026, at 12:30 AM UTC