Microsoft Teams goes down after Microsoft forgot to renew a certificate

Microsoft Teams went down this morning for nearly three hours 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 on 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 authentication certificate has expired causing users to have issues using the service,” explains Microsoft’s outage notification. Microsoft then started rolling the fix out at 11:20AM ET, and by 12PM ET the service was restored for most affected users. Microsoft confirmed the fix was successfully deployed at 4:27PM ET.

This was an embarrassing mistake for Microsoft to make for its flagship “Office hub” software, especially as the company started its own TV commercials for Teams recently. It’s also surprising to see Microsoft forget to renew a key certificate for Teams, especially when the company develops software like System Center Operations Manager to monitor for things like certificate expiration.

Update, February 3rd 4:40PM ET: Added confirmation from Microsoft that the fix was successfully deployed.


Microsoft not using SCOM to monitor their own servers is all sorts of irony.

SCOM is kinda bad for monitoring anyway. It’s a pig to get any great setup out of it and it’s really bloated.

That said there are loads of monitoring solutions for cert expiry as it’s something everyone has been caught of guard with at some point in IT.

Glad to know it wasn’t just me that was having issues.

It is back up now

This has been my experience with Microsoft Teams all the way. It is mostly just OK, but they have the weirdest issues, and things like this make me wonder how much effort they are putting into it. The desktop app is bulky and their search is just bad. There is no way to jump back to a specific day in history without literally scrolling the whole way back up, and then sometimes it just jumps back to the bottom again. It’s never quite bad enough to switch off to something else though, since you can get it with office 365.

I’ve had the same experience. It does, indeed, feel like they don’t put much effort into it. Some of the user interface oddities are embarrassing for a company like Microsoft.

Our corporate thinking heads have imposed Skype for business upon us. You haven’t seen bad design and "don’t care" product unless you’ve used Skype for business – particularly on iOS (try having synced messages between desktop and mobile, or clearing multiple messages on iOS, etc. ). All basic functionality that’s been missing forever in an app that no one cares about – at least not their developers

Wasn’t Skype for Business deprecated and moved into Teams?

Both desktop and iOS versions get regular updates and our company pays big bucks for this as part of bigger Microsoft package so it doesn’t seem to be deprecated.

Skype for Business Online has an end-of-life of July 2021. Skype for Business Server will be supported at least until 2025 and probably beyond. The VOIP functions, especially how integrated it is into hardware, is not going away any time soon. Basically any place where Teams can replace SfB it will, and soon, but in many areas there is a good amount of work to be done still.

SfB cannot die soon enough. And where I work there is no choice but to use SfB and put up with its shortcomings. Every. Day. It’s like some sick experiment/joke meets groundhog day

Trying to make use of search results in Teams is infuriating and inexcusable.

It’s never quite bad enough to switch off to something else

Unfortunately for Slack, this is still true.

"Entrust all of your cloud services to us!"

Some guy is on vacation right now remembering that one last thing he forgot to do before he left…

If it’s up to one guy to remember, your processes have failed you.

You’re ruining my joke!

Sorry, I’ve seen this happen in more than one company lol

reminds me when Microsoft forgot to renew the domain Hotmail and some guy bought it years ago.


I see what you did there…

This isn’t the first time they have had expired certs. Though last time it took out Azure storage.

Lol, since they apparently never learned their lesson, I guess there’s no consequences at MS for embarrassing the whole company like that.

Yeah.. because it’s definitely the same person..

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