User Impact: Some users in Europe may have been unable to access Microsoft 365 services.
More info: Users who were able to access the service may have experienced degraded performance such as latency or error messages.
Impacted services included, but were not limited to:
SharePoint Online
OneDrive for Business
Microsoft Teams
Microsoft 365 admin center
Microsoft Planner
Yammer
Final status: After a period of extended monitoring, we've confirmed that impact has been remediated.
Scope of impact: Impact appears to have affected users located in the United Kingdom, however, we've also received of reports of impact from other European countries.
Start time: Friday, December 11, 2020, at 2:00 PM UTC
End time: Friday, December 11, 2020, at 3:55 PM UTC
Preliminary root cause: Network traffic components weren't processing traffic as expected, which resulted in impact.
Next steps:
- We’re reviewing the service code and recent changes made within the network infrastructure to isolate the source of the issue.
- We're analyzing performance data and trends on the affected systems to help prevent this problem from happening again.
We'll publish a post-incident report within five business days.