Microsoft 365 Alert – Service Degradation – Exchange Online – Some users may be unable to create new online meetings from shared calendar events in Exchange Online – RESOLVED

Announcements Shagufta Naaz

01/06/2026 08:49:00 AM

NHSmail Reference: INC46838876

Microsoft Reference: EX1327187

Issue Status: RESOLVED

Issue Description: Users may be unable to create new online meetings from shared calendar events in Exchange Online.

More info: Affected users can create online meetings from their personal calendars as an alternative method, and existing shared calendar events remain unaffected.

Final Update: 15/06/2026 08:58:00 AM – Microsoft has confirmed that the fix to address the impact to the authorization component of the calendar service has completed and, after monitoring service health metrics to ensure the associated failures have ceased, they have verified the impact is remediated.

Scope of impact: Impact is specific to some users attempting to create new online meetings from shared calendar events in Exchange Online.

Root cause: A recent service update in Exchange Online introduced an issue within an authorization component of the calendar service, resulting in impact.

Next steps : Microsoft are reviewing our updates standards to ensure similar issues are identified and corrected ahead of deployment to prevent this from reoccurring.