Microsoft suffered a prolonged disruption that began around midday on 12 November, when Outlook users worldwide began reporting that the service was down. The outage hit Exchange Online, which handles Outlook email and calendars for businesses, and the damage spread quickly to Outlook, Copilot, Calendar, SharePoint, Planner and other parts of Microsoft 365. Sources describe it as unprecedented in length and severity for one of the world's largest technology companies.

More than 24 hours after the failure began, full service capacity had still not been restored, even regionally. Third-party apps that plug into Microsoft 365 were also affected, with OpenAI flagging broken connections and tools in its Microsoft connectors. Government agencies in California and courts and schools in Australia reported disruption, and an estimated 450 million people use Microsoft 365 apps globally.S2

Microsoft initially tried a standard fix, restarting servers and rebooting systems, but this did not work. Microsoft said the outage was not a cyber attack and promised a full incident report in due time. Sources report that a network change broke the systems, with the recovery proving much harder than expected, and Australian Home Affairs Minister Tony Burke compared the fault in some ways to the CrowdStrike outage in 2024, where a faulty update caused widespread problems.S2

Commentary published by Inc. argues that the outage highlighted the value of older, traditional work habits in an increasingly digital office, an argument framed around how workers coped when their digital tools went offline.S1