Microsoft 365 Outage History

A code regression in a Microsoft 365 service update caused some users in Europe to receive "Page not found" errors when accessing Exchange Online through Outlook on the web for 1.7 hours. Users reported being repeatedly logged out of Microsoft services during the incident. Microsoft resolved the issue by rolling back the problematic update, while users could access their email through Outlook desktop or mobile clients as a workaround.

Microsoft OneDrive users experienced issues loading the search bar functionality for 3.3 hours. The incident affected any user attempting to use the search feature in OneDrive, with some users also reporting Exchange 365 not loading while other admin portals remained functional. Microsoft resolved the issue by identifying and rolling back a recent change that was contributing to the problem.

Users experienced issues loading the search bar in SharePoint Online sites, preventing them from using search functionality across the platform. Microsoft identified and rolled back a recent change that was contributing to the problem after reproducing the issue in their environment. The incident lasted 4.1 hours and was resolved through the rollback while Microsoft monitored service health to confirm the fix.

Microsoft 365 users experienced issues accessing web-based services when using Google Chrome Version 147, with problems including missing UI elements, failed page loads in the admin center, and inability to open Excel/PowerPoint files through web pages. The issue was isolated to Chrome browsers, while Microsoft Edge and other browsers remained unaffected. Microsoft resolved the incident by updating authentication components across service endpoints, with users needing to refresh their browser pages to experience relief.

An authentication component misconfiguration disrupted the Autodiscover flow for Exchange on-premises connections, preventing some users from accessing email messages through Outlook Mobile for 71.9 hours starting April 10, 2026. Microsoft identified the root cause and was developing a fix to correct the misconfiguration that was blocking Outlook Mobile from automatically establishing access for affected users. The incident had minor status and impacted users attempting to connect to Exchange on-premises environments through the mobile application.

Microsoft 365 services including Teams and Outlook experienced disruptions due to a network-level issue caused by an external service dependency, affecting users in the US, Netherlands, UK, and Canada. Users reported being unable to access email and encountering login problems with Outlook requiring repeated authentication. Microsoft identified and corrected the network disruption, with services recovering within approximately one hour, though some users experienced brief email delivery delays during the recovery process.

A recent code deployment caused a small subset of Microsoft 365 administrators in North America and Brazil to be unable to access the Microsoft 365 admin center for 4.6 hours. Microsoft identified the problematic deployment and resolved the issue by reverting the changes across their infrastructure. The incident was triggered by user reports of access issues that exceeded normal alerting thresholds.

Some Microsoft 365 users were unable to access the Microsoft 365 web sign-in page and Microsoft 365 Copilot web sign-in page due to service infrastructure not processing traffic efficiently. The issue affected users served through specific infrastructure components, while application-based Copilot services remained accessible. Microsoft implemented configuration changes to address the inefficient traffic processing, with partial recovery observed after 5.3 hours.

Microsoft 365 administrators in the Central US region experienced inability to access or delays when accessing the Microsoft 365 admin center for 3.1 hours due to infrastructure in the Central US datacenter entering a degraded state. Users reported login failures and "service unavailable" messages when attempting to access the admin portal. Microsoft resolved the issue by rerouting traffic away from the affected systems after initial infrastructure restarts proved insufficient.

Microsoft 365 users experienced intermittent issues accessing their Exchange Online mailboxes through Outlook mobile apps and the new Outlook for Mac desktop client over a 33-hour period. The incident was caused by problems with the Notification Broker service in the Exchange Online infrastructure. Microsoft resolved the issue by restarting the Notification Broker service across affected infrastructure and implementing code changes to address contributing factors.