Microsoft Teams has suffered an embarrassing outage this morning, although the fix is already being deployed, according to Microsoft.

Shortly after 9:00 a.m. this morning, Microsoft announced via its Microsoft 365 Status Twitter account that some users were unable to access Teams and that techs were looking into it.

“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”

Approximately an hour later, Microsoft updated their Twitter feed to announce the cause of the problem. Evidently, an expired authentication certificate was at fault.

“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.”

By shortly after 11:00 a.m. ET, Microsoft began rolling out an updated certificate that should address the problem.

“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 has been working hard to grow its Teams user base, taking on rival Slack. It’s a safe bet Slack will pounce on what could be considered a rookie mistake by Microsoft to tout the reliability of its own service.