Microsoft Teams went down because of an expired certificate

It seems like a pretty basic thing for Microsoft to forget.

This morning, Microsoft Teams went down for a few hours, and it seems that a pretty rookie mistake is to blame. Microsoft apparently forgot to renew the SSL certificate, which allows a secure connection between a web browser and a web server. As a result, the app told users that it failed to establish an HTTPS connection to Microsoft's servers.

It's odd that Microsoft would forget to renew a critical authentication certificate, and it was rude timing, as so many were attempting to log in and start their week.

Almost three years old, Microsoft Teams is the company's Slack competitor. Last year, it added new features like private channels and custom video chat backgrounds, and it recently launched its first TV ad campaign. Needless to say, today's outage probably doesn't help in Microsoft's efforts to take on Slack.