Microsoft is working on fixing an ongoing and widespread Microsoft 365 outage that is impacting multiple services and features, including Exchange Online, Microsoft Teams, and SharePoint Online.

Since this outage started roughly six hours ago, Downdetector has received thousands of reports, with affected users saying they're also experiencing problems connecting with other services, such as OneDrive, Purview, Copilot, and Outlook Web and Desktop.

"We're investigating an issue impacting users attempting to access Exchange Online or functionality within Microsoft Teams calendar. For more information, please refer to MO941162 in the admin center," the company said when it acknowledged the issues 6 hours ago.

"While we continue to work on mitigating the issue, we've added a comprehensive list of impacted services and scenarios to the more info section."

In the admin center incident report, Microsoft confirmed that the outage prevents customers from accessing Exchange Online via Outlook on the web, Outlook desktop client, Representational State Transfer (REST), and Exchange ActiveSync (EAS).

The company also says some customers might have issues performing actions within Microsoft Fabric, Microsoft Bookings, and Microsoft Defender for Office365.

While Remond has only shared that the outage was caused by a "recent change," the company has already deployed a fix on the impacted infrastructure, restarted impacted systems, and is monitoring the situation.

"We've started to deploy the fix which is currently progressing through the affected environment. While this progresses, we're beginning manual restarts on a subset of machines that are in an unhealthy state," Microsoft said one hour ago.

"We're monitoring the progress of the fix, which has been deployed to approximately 60% of the affected environments. We're continuing our manual restarts on the remaining impacted machines."

Microsoft's Office service health and the Microsoft 365 network health status pages currently show no issues with the company's network health status and availability, internet service provider availability, and the customer's network infrastructure.

In July, another worldwide outage took down multiple Microsoft 365 and Azure services, including the admin center, Intune, Entra, Power BI, and Power Platform services.

One day later, the company admitted that the nine-hour outage was triggered by a distributed denial-of-service (DDoS) attack.