Users of some of the most popular online workplace tools, including Microsoft Teams and Outlook, have reported issues logging on to the services - with the outage apparently down to a new Windows 10 update.
Following the release of a recent Windows 10 1909 cumulative update, a number of Microsoft 365 services have seen issues with users unable to log in and gain access.
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Microsoft 365 error
Users across the range of Microsoft 365 services reported seeing a message stating "We ran into a problem. Reconnecting…" before being asked to restart the program, with the same screen also displaying an error code 80080300.
Microsoft says it has tracked down the issue, which it says it caused by the Windows 10 1909 KB5003169 cumulative update released as part of its recent May 2021 Patch Tuesday updates.
The company says that only a small number of users will be affected by the issue, but is advising anyone confronted with the error to simply restart Windows 10 again after the initial update finishes installing.
"We've received reports that some users on Windows Update KB 5003169 are unable to connect to various Microsoft 365 desktop clients including Microsoft Teams, Outlook, and OneDrive for Business," a Microsoft 365 advisory explained.
"Our investigation has determined that a code issue exposed by a recently deployed Windows update, detailed in KB 5003169, is causing the problem."
Anyone who continues to encounter issues should log in to the web-based versions of the tool they are trying to use whilst Microsoft carries out further investigations.
Microsoft's most recent Patch Tuesday updates included a number of security fixes and quality improvements, including patching at least three zero-day vulnerabilities and 52 other security issues.
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