Microsoft 365 said service stability was improving after a major outage that affected more than 430 million people worldwide, and that capacity had increased following recent traffic optimisation actions. The company posted on X on Friday, 13 November that it was “implementing these actions more broadly across affected regions as we seek to attain persistent recovery,” but warned a complete fix was likely to take more time.
Microsoft outage impact and cause
The outage, which began on Thursday, lasted more than 12 hours and left millions unable to access Outlook email, Teams meeting tools and other core services. Monitoring site Downdetector recorded issues in at least 74 countries. Banks, governments and courts in multiple countries were affected.
Redmond, Washington-based Microsoft attributed the disruption to “elevated load” on its infrastructure: a large number of servers became “unexpectedly unavailable,” sending added traffic to remaining servers and straining them. The company said a cybersecurity breach did not cause the outage.
Recovery efforts and outlook
Microsoft said it had seen “partial recovery” in regions where fixes were applied, and that restored servers were stable as it shifted traffic to alternate routes while working to bring remaining affected servers back online. Earlier in the day the company had said the fix “was not taking as expected” and that it was identifying alternate workstreams to apply.
The firm said it has “engaged in multiple workstreams to alleviate impact” and return services to a “healthy state.” “As capacity is restored, users may experience a gradual recovery as their clients reconnect,” Microsoft wrote. Once the incident is mitigated, the company said it will provide a Post‑Incident Report with full details of the root cause, defence-in-depth repair items and more.
The outage also disrupted business operations that rely on Microsoft systems. According to Microsoft’s website, more than 90% of Fortune 500 companies use its Copilot AI chatbot. Some Indian companies preparing or already reporting quarterly results were reported to be in a wait-and-watch mode as they planned calls with investors and analysts.
