Microsoft said Friday it had addressed the underlying cause of a global Microsoft 365 outage that disrupted Outlook, Teams and Copilot for more than 21 hours, tracing the breakdown to an issue introduced during an earlier network capacity upgrade that surfaced after a recent network change. The company said it was continuing to restore service to remaining customers and regions and reiterated that there was no indication of malicious activity.
Before the fix took hold, the disruption continued to widen across public services, courts and businesses on Friday. UK pharmacies warned patients of possible prescription delays, New York paused Friday evictions, UN climate delegates shifted communications to WhatsApp, and Sao Paulo’s state court suspended legal deadlines as Brazil’s bar association asked the Supreme Federal Court to follow suit.
The outage began Thursday at 16:17 UTC and generated problem reports across 74 countries and territories, with Downdetector logging nearly 140,000 complaints for Outlook alone at the peak. Early recovery efforts faltered overnight after servers failed automated health checks and froze again once traffic returned, prompting Microsoft to pause all deployments, reroute traffic and extend its email timeout window to 48 hours so queued messages would not bounce.
