Microsoft 365 Alert – Service Degradation – SharePoint Online – Guest users are unable to access SharePoint Online sites connected to Microsoft Teams – RESOLVED

26/08/2026 08:59:00 AM

NHS.net Connect Reference: INC46918773

Microsoft Reference: SP1461217

Issue Status: RESOLVED

Issue Description: Guest users are unable to access SharePoint Online sites connected to Microsoft Teams.

More info: Specifically, guest users were redirected to an AccessDenied.aspx page when attempting to access SharePoint Online sites where access is granted through Microsoft 365 Groups.

As a potential workaround, admins could have manually added affected guest users directly to the SharePoint Members group instead of relying on Microsoft 365 Group membership propagation.

Final Update: 26/08/2026 02:10:00 PM – Microsoft has completed a period of monitoring service telemetry, and they have observed the restoration of service availability to normal levels. Additionally, during this time, Microsoft has received multiple reports from previously affected customers that they’re experiencing relief from impact, and as such, Microsoft has determined this incident is resolved.

Scope of impact: This issue could have impacted any guest users attempting to access SharePoint Online sites where access is granted through Microsoft 365 Groups.

Root cause: A recently deployed change interacted with dynamic claims process, causing impact.

Next steps: Microsoft is conducting a review of their internal change management processes to ensure the appropriate controls are in place and to reduce the likelihood of similar issues occurring in the future.

They will provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business days.