Preemptive Outage Report: Microsoft Endpoint Failures

Microsoft Teams Channel Access Issue — Resolved

Status: Resolved
Duration: Aug 27, 2026, 3:22 PM – 11:29 PM EDT

Summary
Some Mio users in North America may have had trouble accessing or managing Microsoft Teams channel features, including viewing shared and private channel membership, due to an incident on Microsoft's side. This was not an issue with Mio's own systems.

Resolution
Microsoft has confirmed the issue is fully resolved. The root cause was a processing delay within Microsoft Teams infrastructure that caused requests to exceed their retry window, creating a backlog of failed events. Microsoft disabled the affected processing components to stop new requests from adding to the backlog, then confirmed via monitoring that the backlog had cleared.

Teams channel features should now be working normally for all affected users. No action is needed on your end.

We'll continue monitoring and will post again if anything resurfaces.

We are investigating elevated failures (https://admin.cloud.microsoft/?#/servicehealth/:/alerts/TM1462874) when reauthorizing and refreshing Microsoft subscriptions. The issue appears to originate from Microsoft’s backend services.

There is currently no known impact to end-user performance or functionality. No customer subscriptions have been confirmed as permanently failed, and the system’s retry and fallback mechanisms are continuing to operate.

No customer subscriptions were confirmed to have permanently failed as of the latest assessment. However, if the Microsoft errors persist and retry attempts are exhausted, affected subscriptions could stop receiving events until they are recreated or refreshed.

What Mio is doing:

Monitoring reauthorization and refresh success rates

Retrying failed operations through the existing lifecycle process

Tracking subscriptions that may exhaust their retry attempts

Coordinating with Microsoft and providing request identifiers for investigation

Preparing a bulk refresh operation after Microsoft’s service stabilizes, if required