Microsoft: Teams Outage Mostly Resolved After Four Hours

The worldwide outage had affected the Teams collaboration app along with ‘multiple’ other Office 365, Azure and Dynamics 365 services.


Microsoft reported that the widespread outage to Teams, Azure and other services on Monday was largely resolved after about four hours.

“Service health has improved across multiple Microsoft 365 services,” with only “isolated residual impact” remaining among users, the company said in a tweet from the Microsoft 365 Status account at 7:19 p.m. Eastern Time.

[Related: Partners: Office 365 Outages Suggest Microsoft Is Getting Overwhelmed]

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The outage appears to have begun at about 3:30 p.m. Eastern Time on Monday, when user reports of Teams issues began to climb on Downdetector, a website that tracks outages. Shortly after that, Microsoft disclosed the Teams and Azure outage on the Microsoft 365 Service health status page and on Twitter.

The Redmond, Wash.-based company reported that the issues Monday had impacted “any service” that uses Azure Active Directory, Microsoft’s widely used identity authentication solution.

Ultimately, the issues had the potential to “affect any user” worldwide, Microsoft said.

The company indicated that the biggest impact was on the Microsoft Teams collaboration app--an essential tool for countless businesses with its chat, audio and video calling, and document-sharing functionality.

However, along with bringing Teams down for many users, the outage Monday left many users “unable to access multiple Microsoft 365, Azure, and Dynamics 365 services, including the Service Health Dashboard,” according to Microsoft.

“Any service that leverages Azure Active Directory (AAD) may be affected,” the company had said in the midst of the outage Monday.

A map on Downdetector had shown the Teams outage affecting cities including New York, Washington, Chicago, Toronto, San Francisco, Los Angeles and Seattle.

Microsoft blamed the outage on a “recent change to an authentication system.” The company said it was rolling back the update to mitigate the impact as of 4:11 p.m. Eastern Time.

At 5:57 p.m. Eastern Time, Microsoft said it had finished deploying the update to all regions that had been impacted—and as of that time, user reports about Teams issues to Downdetector had mostly dissipated.

“While service health has improved and many users are no longer experiencing problems, we’re taking further steps to identify and remediate isolated residual impact for all Microsoft 365 services including Teams, Exchange services, SharePoint Online,, and the admin portal,” Microsoft said on the Microsoft 365 Service health status web page.

It was at least the third time that major issues have affected the Teams collaboration app since the beginning of February. Microsoft reported issues with delays in receiving Teams chats on Feb. 17, and with joining Teams meetings on Feb. 4.

Service health has improved across multiple Microsoft 365 services; however, we are taking steps to resolve some isolated residual impact for services that are still experiencing impact. Additional details can be found at or under MO244568 if available.

— Microsoft 365 Status (@MSFT365Status) March 15, 2021

The Microsoft outage on Monday is another example of the negative business impact when customers put all their “eggs into the public cloud basket,” versus taking a hybrid cloud approach that includes their own infrastructure, said Bob Venero, CEO of Holbrook, N.Y.-based solution provider Future Tech, No. 96 on CRN’s Solution Provider 500 for 2020.

Venero told CRN that he sees the outage as another reason to advise his customers to invest in on-premise infrastructure for mission-critical applications.

“If you look at what is mission-critical for most companies, No. 1 is financials and No. 2 is communications infrastructure, which is often Exchange and Teams,” Venero said. “The problem with an outage like this is it is very difficult to get answers for customers who have outsourced their IT to a public cloud provider-- rather than in-sourcing their IT to a trusted advisor like Future Tech.”

Teams—which is part of Microsoft’s Office 365 suite of productivity apps—had reached 115 million daily active users worldwide as of late October, Microsoft disclosed at the time. That was a more than 5X increase from roughly a year earlier, when Teams had 20 million daily active users, according to Microsoft.