Microsoft 365 Alert – Service Degradation – Microsoft 365 suite – Some users may be unable to view or access Microsoft 365 apps or services – RESOLVED

20/04/2023 16:09:00 PM (GMT)

NHSmail Reference : INC35427107

Microsoft Reference : MO544165

Issue Status : RESOLVED

Issue Description : Some users may be unable to view or access Microsoft 365 apps or services.

More Information : Impacted services may include but are not limited to:
– Microsoft 365 Online apps – Users may be unable to access Microsoft 365 web apps, such as Excel Online. Additionally, the search bar may not appear in any Office Online service.
– Microsoft Teams – Users may be unable to access the Microsoft Teams admin center.
– SharePoint Online – Users may be unable to view the settings gear, search bar and waffle.
– Microsoft Planner – Users may be unable to access Microsoft 365 web apps through Microsoft Planner.

Final Update : 21/04/2023 09:25:00 AM – After extended monitoring and receiving confirmation from previously affected users, Microsoft have validated that adding further processing throughput successfully resolved the issue.

Scope of impact : Impact is specific to some users who are served through the affected infrastructure.

Root cause : A section of caching infrastructure is performing below acceptable performance thresholds, causing calls to gather user licensing information to bypass the cache and go directly to Azure Active Directory infrastructure resulting in high resource utilization, resulting in throttling and impact.

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