Microsoft Teams goes down after Microsoft forgot to renew a certificate

Microsoft Teams is currently down worldwide after Microsoft forgot to renew a critical security certificate. Users of Microsoft’s Slack competitor were met with error messages attempting to sign into the service Monday morning, with the app noting it had failed to establish an HTTPS connection to Microsoft’s servers.
Microsoft confirmed the Teams service was down just after 9AM ET today, and then later revealed the source of the issue.“We’ve determined that an authenticat