Several Microsoft Office products and programs, including email client Outlook, were knocked offline for several hours Monday.
The outage was first reported by Twitter users, most of whom complained that Outlook was not working. Data from downdetector.com indicated that Outlook and Microsoft’s wider range of Office products were affected.
Microsoft said Monday evening that it had identified the issue (an authentication error) and was attempting to rollback recent changes, but that the outage would continue for some time longer.
We’ve rolled back the change that is likely the source of impact and are monitoring the environment to validate that service is recovering. Please visit https://t.co/AEUj8uAGXl for additional information on this issue.
— Microsoft 365 Status (@MSFT365Status) September 28, 2020
However, users who were logged in before the rollback occurred were not affected.
“Existing customer sessions are not impacted and any user who is logged in to an existing session would be able to continue their sessions,” Microsoft added in a status update on the Office 365 website.
The outage came at a bad time as many workers in the U.S. continue to work from home because of the coronavirus pandemic, which has caused huge surges in at-home internet use. In the earliest days of lockdown restrictions being put in place, many states’ unemployment services web portals crashed because of the dramatic increases in traffic and applications. Similar influxes of users have plagued school websites this fall as students continue to adapt to remote learning.
Experts believe the work-from-home trend will continue long after the coronavirus ends.