Microsoft Teams, the popular workplace chat app, has gone down in the middle of the working day. Users complained that they were unable to get online or talk to colleagues in what appeared to be a widespread outage. But soon after the problems were identified, many appeared to be able to get back online again. The problems began around lunchtime in the UK, and around the time that many in the US are beginning work, according to tracking website Downdetector. Numerous users complained on that site and elsewhere that they were unable to get online, particularly using their browser. Many of those users were hit by a mysterious message reading: “Operation failed with unexpected error”. Others saw similarly vague messages about not being able to connect to the internet or indistinct error codes. Microsoft confirmed on its official account that it was aware of an issue where “some users may be unable to access Microsoft Teams using web browsers”. But numerous users complained that they were unable to get online through the desktop app, either.