Microsoft Teams went down early Monday morning, gumming up the start of the week for millions of workers who rely on the tech giant’s chat and collaboration tool.
Microsoft first acknowledged the issue just after 6 a.m. Pacific in a tweet.
We're investigating an issue where users may be unable to access Microsoft Teams. We're reviewing systems data to determine the cause of the issue. More information can be found in the Admin center under TM202916
— Microsoft 365 Status (@MSFT365Status) February 3, 2020
A little more than an hour later, Microsoft noted that an expired authentication certificate caused the outage. Microsoft said it is working on a new certificate and has begun deploying it to get Teams back online.
We've determined that an authentication certificate has expired causing, users to have issues using the service. We're developing a fix to apply a new certificate to the service which will remediate impact. Further updates can be found under TM202916 in the admin center.
— Microsoft 365 Status (@MSFT365Status) February 3, 2020
The Verge called the Teams outage an “embarrassing mistake,” noting that Microsoft develops tools that monitor issues like certificates expiring, so it shouldn’t let certificates lapse for key programs like Teams.
Teams has 20 million daily users, and Microsoft is locked in a tense battle with Slack. Microsoft has put a lot of energy to Teams, recently launching a TV ad campaign to create more awareness of the tool.
