Microsoft outage locks users out of Outlook, Teams and more

29 Sep 2020

Image: © prima91/

After a global outage, many users experienced difficulties signing into Microsoft 365 services.

Microsoft has said issues are resolved after an outage yesterday (28 September) prevented users around the world from using its cloud-based services, including Outlook and Teams.

Last night, the company tweeted that it was investigating “an issue affecting access to multiple Microsoft 365 services”. Microsoft said users that were already logged into a particular platform should be able to continue using it, but there was an authentication issue preventing users from signing in.

“We’re working to identify the full impact and will provide more information shortly,” it said. Soon after, Microsoft reported that it had narrowed the user-authentication problems down to a “recent change”.

Having rolled that change back, however, the situation did not improve. Microsoft opted to redirect traffic to “alternate infrastructure” while it investigated the outage.

In the early hours of this morning, the company said it was seeing improvements for multiple services. At 5am it tweeted: “We’ve confirmed that the residual issue has been addressed and the incident has been resolved. Any users still experiencing impact should be mitigated shortly.”

Users can check the Microsoft 365 health status page to learn more.

This isn’t the first major outage reported by Microsoft this year. When thousands began to work from home in March, Teams users across Europe experienced “messaging-relating functionality problems”.

At the time, corporate vice-president for Microsoft 365, Jared Spataro, said that the company had seen a 500pc increase in Teams meetings, calling and conferences and a 200pc increase in its use on mobile devices.

In April, the number of daily Teams users passed 75m as a record number of businesses pivoted online in response to Covid-19 restrictions.

Last week, Microsoft announced new features for Teams at its virtual developer conference Ignite. This included the introduction of ‘virtual commutes’, breakout rooms, and access to meditation and mindfulness resources.

Lisa Ardill was careers editor at Silicon Republic until June 2021