User impact: Users may have been unable to view or access Microsoft 365 apps or services.

More info: Impacted services included but were not limited to:
– Microsoft 365 web apps – Users may have been unable to access Microsoft 365 web apps, such as Excel for the web. Additionally, the search bar may not have appeared in any Office for the web service.
– Outlook on the web – Users may have experienced slowness or latency when accessing or using the service.
– Microsoft Teams – Admins may have been unable to access the Microsoft Teams admin center. Users may have been unable to launch the Developer Portal. 
– SharePoint Online – Users may have been unable to view the settings gear, search bar, and waffle.
– Microsoft Planner – Users may have been unable to access Microsoft 365 web apps through Microsoft Planner.
– Microsoft Yammer – Users may have been unable to view the search bar.
– Project for the web – Users may have been unable to view the waffle menu, settings, and help content.
– Microsoft Power Apps – Users may have been unable to access Power Apps from the Office.com app launcher.

While the Microsoft 365 apps may not have rendered, users could have accessed the applications directly through URL. Some examples of these included:
Microsoft 365 admin center – admin.microsoft.com 
Microsoft Teams – teams.microsoft.com
Outlook for the web – outlook.office.com
Microsoft Power Apps – make.powerapps.com
Word for the web – microsoft365.com/launch/word
Excel for the web – microsoft365.com/launch/excel

Final status: After extended monitoring and receiving confirmation from previously affected users, we’ve validated that adding further processing throughput successfully resolved the issue.

Scope of impact: Impact was specific to some users who were served through the affected infrastructure. The majority of reported impact stemmed from users located in North and South America.

Start time: Thursday, April 20, 2023, at 12:38 PM UTC

End time: Thursday, April 20, 2023, at 6:50 PM UTC

Preliminary root cause: High resource utilization on the infrastructure which supports the affected services resulted in the end-user impact.

Next steps:
– We’re continuing to investigate the underlying cause of the high resource utilization which led to the impact.
– We’re monitoring service telemetry to ensure impact doesn’t recur.

We’ll publish a post-incident report within five business days.