A major global outage occurred on Microsoft 365, Microsoft’s cloud service for businesses. Recovery efforts progressed on the evening of 13 October Japan time, and reports said that the service remained relatively stable that night in regions including Japan.
A major outage occurred on Microsoft 365 from US software giant Microsoft, affecting multiple services including Outlook, Teams, Copilot and SharePoint. Initially, the outage was considered to be primarily limited to the United States, but the possibility that all regions could be affected was later indicated. Recovery efforts were reported to be under way on the afternoon of 13 October Japan time. Recovery was reported to have been completed in parts of the Asia-Pacific region at 8 p.m., and Japan was announced to be in a relatively stable state at around 9 p.m.
The reported cause was the unexpected unavailability of multiple servers, resulting in health-check failures. This caused communications to become concentrated on other servers, creating a heavy load and affecting overall operations. No physical equipment failures have been confirmed at this point, and recovery efforts are being made through measures including restarts and adjustments to load balancing. Microsoft Japan said that the possibility of a cyberattack had “not been confirmed.”
Impacts in Japan and overseas have also been reported, with some users in Japan experiencing restrictions on email use and other services from the morning of the 13th. There have been reports that some US government agencies, universities and businesses experienced operational disruptions, and attention is focused on the status of the resumption of operations and any expansion in the scope of the impact. While users have posted successive reports of recovery on social media, some observers believe that full recovery will still take time.