Microsoft 365 Alert – Service Degradation – Microsoft 365 suite – Users may experience issues when utilising multiple Microsoft 365 services – RESOLVED
01/09/2026 09:07:00 AM
NHS.net Connect Reference: INC46923180
Microsoft Reference: MO1465074
Issue Status: RESOLVED
Issue Description: Users may experience issues when utilising multiple Microsoft 365 services.
More info: Impact is fully resolved. Previously identified impact included the services and scenarios listed below.
RECOVERED
Microsoft Graph:
– Users may have experienced failures for scenarios that rely on access to Exchange Online data.
Exchange Online:
– Service telemetry indicates recovery of core mail flow and search functionality.
– Service telemetry indicates recovery of the majority of previously impacted authentication and protocol connectivity scenarios.
– Users may have been unable to connect to, or experience degraded functionality, such as failures when attempting to use the search function, within Exchange Online. All connection methods were affected.
– Users may have been unable to connect to Exchange Web Services (EWS)
– Users may have been unable to use room finder in Outlook calendars.
– Users couldn’t download email message attachments through any Exchange Online connection method.
– Users may have been unable to sign in to Outlook on the web.
Outlook for iOS and Android:
– Users may have experienced delays or failures when sending or receiving email messages via Outlook for iOS and Android.
Microsoft 365 Admin Center:
– Admins may have experienced issues authenticating into the admin center.
Microsoft Purview:
– Users can now access the Microsoft Purview portal.
– Any policy hits, alerts, or processing activities delayed during the event are expected to appear over the next 24 to 48 hours as recovery validation continues.
– From a Microsoft Purview Communication Compliance perspective, the issue has been mitigated, and customers should now be able to access and use the portal as expected. They are currently processing any policy activity that may have been delayed during the event, and any missed policy hits, alerts, or related results are expected to appear within the next 24 to 48 hours.
Microsoft Defender XDR:
– Users may have experienced intermittent authorisation failures across solutions in Defender.
Microsoft Teams:
– Users may have experienced issues with search and users’ presence may have been stale and not updated automatically or through manual adjustment. User location adjustment may have failed.
– Users may have experienced issues with Microsoft Teams Room (MTR) devices and desktop phones displayed offline in the Teams admin center.
– Users may have experienced issues creating, deleting, and editing Teams channels.
– Users may have experienced issues with calendar functionality.
Microsoft 365 Copilot:
– Users’ Copilot prompts that required Microsoft 365 grounding, such as email content, may have failed.
– Users may have experienced failures for scenarios that rely on access to Exchange Online data.
– Users prompts may have failed or they may have experienced degradation when utilising Cowork.
OneDrive for Business and SharePoint Online:
– Users may have been unable to load or refresh portions of OneDrive and SharePoint, including account and storage information, search results, Favorites, Followed and Shared With Me content, recent files, lists, and news.
– Some users may have also experienced delayed or failed file opening, Office policy-label retrieval, OneDrive synchronisation, mobile camera upload, and video playback.
– Users may have seen partial page failures, missing or stale content, repeated retries, and operation timeouts rather than a complete platform outage.
Universal Print:
– Users may have been unable to create, upload, or retrieve print jobs.
Final Update: 04/09/2026 10:32:00 AM – Based on Microsoft’s telemetry all previously impacted services have remained healthy since impact was remediated on Thursday, September 3, 2026, at 10:00 AM UTC, and this issue is resolved.
Scope of impact: Users attempting to perform any of the outlined impact scenarios may have been affected by this event.
Root cause: An issue within a core authentication configuration used by multiple Microsoft 365 services was resulting in impact.
Next steps: Microsoft is evaluating their core authentication configurations to prevent the recurrence of similar impact in the future. In addition, they are further reviewing their monitoring systems to ensure they identify and are expediently alerted to these types of scenarios.
They will provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business days.
