Microsoft 365 Alert – Service Degradation – Microsoft Teams – Admins or those with the Guest inviter role may be unable to add guest users as members in Microsoft Teams – RESOLVED

07/02/2025 08:40:00 AM

NHSmail Reference: INC46469831

Microsoft Reference: TM1024881

Issue Status: RESOLVED

Issue Description: Admins or those with the Guest inviter role may be unable to add guest users as members in Microsoft Teams.

More info: Admins modify the guest invite settings to allow anyone to add guest users as members as a work around to this issue.

Final Update: 11/03/2025 09:05:00 AM – Microsoft have completed the deployment of their fix and confirmed after monitoring service health telemetry that errors associated with impact have ceased, confirming impact remediation.

Scope of impact: Impact is specific to admins who are served through the affected infrastructure and are attempting to add guest users as members within Microsoft Teams.

Root Cause: A recent optimization update removed a portion of code necessary to allow admins and Guest inviters the ability to add guest users as member in Microsoft Teams, resulting in impact.

Next steps: Microsoft are reviewing their update testing and validation procedures to identify opportunities to improve impact detection and prevent similar future occurrences.