Microsoft Corp. was left with egg on its face today after an outage took its Microsoft Teams communications platform offline for around three hours this morning.

Microsoft Teams, a messaging platform that offers chat, video meetings and file storage, is widely used by business workers as their primary collaboration tool. But today, users trying to sign into the service were met with error messages saying it had failed to establish an HTTPS connection to Microsoft’s servers.

Microsoft first admitted there was a problem via a tweet at 6 a.m. PST:

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

About an hour later, the company provided an update, revealing a rather embarrassing reason for the outage: an expired security certificate.

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

And one hour after that, a third tweet said Microsoft was deploying an updated security certificate to get Teams back up and running:

We’ve initiated the deployment of the updated certificate and are monitoring service health as the fix progresses. Additional information can be found under TM202916 in the admin center.

— Microsoft 365 Status (@MSFT365Status) February 3, 2020

Customers soon began reporting that the service had been fully restored.

Microsoft moved quickly to fix the problem and kept users informed with its regular updates, but the company notably failed to apologize for the outage. That may have something to do with the fact that it’s a rather stark failure for Microsoft, which also builds and sells tools that are meant to monitor things such as expiring security certificates, so that these problems never occur.

Constellation Research Inc. analyst Holger Mueller agreed that the episode was a “very embarrassing” one for Microsoft, made worse by the fact that this kind of incident is not new for the company.

“It’s never good when the cloud goes down, especially when it’s caused by one of the most basic IT mechanisms, namely an expired SSL certificate,” Mueller said. “The problem for Microsoft is that this isn’t the first time its cloud products have been hampered due to SSL issues. This will mean that questions around both its automation and control procedures should be a little more critical.”

In any case, the company will surely conduct a very thorough investigation to ensure this doesn’t happen again. Microsoft Teams is currently in the midst of a battle with Slack Technologies Inc. to win the hearts and minds of business users, and preventable outages like this surely won’t do it many favors.

Image: Microsoft