THE CRUNCH
A widespread Microsoft cloud outage that began around 18:00 UTC on November 12 has taken down services including Exchange Online, Teams, Copilot 365 and Defender for Office 365, and the company is still struggling to restore them. Microsoft says a core process on some servers is becoming overwhelmed, causing the machines to stop responding and adding to the capacity loss. Its early fixes have not delivered the expected relief, and there is no timeline for full restoration.
The company's early investigation points to failed automated health checks, possibly originating from a specific component responsible for processing server health. Microsoft says it has not spotted any changes to its systems that might have sparked the incident, though its status page mentions it is assessing whether reverting a small number of recent configuration updates could help.
By around 22:00 UTC, Microsoft said it had validated an alternative health check method that let a subset of affected servers return to service. Its latest update describes a more cautious approach: isolating a portion of infrastructure, restarting affected components and reintroducing traffic to confirm stability before applying the change more broadly.
The outage also hit the tools administrators would normally use to diagnose it, with Intune and the Microsoft 365 Apps Admin Center unavailable alongside the main services. For many customers, email is not flowing at all, and The Register reports working days severely disrupted.