mo1138499

The tag mo1138499 refers to a specific Microsoft 365 incident that caused an outage affecting Office.com and the Copilot assistant. Users across North America experienced access problems, and Microsoft confirmed the critical incident under the identifier MO1138499. The company investigated telemetry and network traces, ultimately mitigating the disruption by reverting a recently deployed configuration change. While some outlets suggested the rollback targeted update KB5038575, this could not be independently verified from Microsoft's public postings. This tag covers discussions and reports about the outage, its impact, and the recovery process.