Overview
- The outage began on Thursday, November 12, and spread worldwide within about an hour, with Downdetector showing reports in roughly 74 countries and U.S. reports peaking near 130,000.
- Microsoft paused deployments, offloaded affected infrastructure, restarted servers and redirected traffic while some early fixes did not produce the expected results.
- Core Microsoft 365 products were affected, notably Outlook, Teams and Copilot, and AI services that use Microsoft connectors such as OpenAI’s ChatGPT and Anthropic’s Claude lost access to mail and calendar data.
- The disruption forced contingency measures at hospitals, governments, airlines and financial firms, slowing patient communications, visa processing and customer service operations in multiple countries.
- After more than 24 hours of work, Microsoft announced full restoration on Saturday, November 14, and the incident has renewed calls for stronger service guarantees, multi‑cloud strategies and local backup plans.