Microsoft 365 elevated error rates

Incident Report for Cronofy

Update

We are still monitoring, waiting for Microsoft to restore service fully.

We are going to stop posting updates for now, until we see the incident resolved. Our service will continue to sync as much as possible, and retry any changes that failed.

Please watch https://status.cloud.microsoft/ for updates from Microsoft on the resolution of the incident.

Posted Nov 13, 2026 - 00:16 UTC

Update

We have still seen no improvement yet.

Sync of Microsoft calendars remains degraded - about 40% of our communications to Microsoft are working, and any failed calls are being retried until they succeed.

Microsoft are reporting under issue reference EX1550543, which you can follow at https://status.cloud.microsoft

We will update this status when we see some improvement or in another 2 hours.

Posted Nov 12, 2026 - 22:03 UTC

Update

We are continuing to monitor the situation but have seen no improvement yet.

Microsoft are reporting under issue reference EX1550543, which you can follow at https://status.cloud.microsoft

We will update this status when we see some improvement or in 2 hours.

Posted Nov 12, 2026 - 19:56 UTC

Update

We are continuing to monitor the situation.

Sync to Microsoft 365 calendars is degraded, so there is some delay between events appearing in calendars. Other providers are not impacted.

We will update this status when we see some improvement, or in an hour.

Posted Nov 12, 2026 - 18:51 UTC

Monitoring

This looks to be as a result of a wider outage with Microsoft's services that has been given issue reference EX1550543.
We'll continue to monitor.

Posted Nov 12, 2026 - 18:27 UTC

Investigating

We are observing Microsoft 365 calendar APIs returning higher error rates and investigating the impact. This may affect how quickly changes to calendars are observed and our ability to push events.

Posted Nov 12, 2026 - 18:07 UTC

This incident affects: Major Calendar Providers (Microsoft 365).