About this tag
Incident TM1200517 refers to a confirmed Microsoft Teams service disruption on December 19, 2025, causing widespread message delays and degraded functionality. Tracked in the Microsoft 365 admin center, the outage generated numerous user reports and outage-tracker spikes. Microsoft initiated telemetry-led recovery steps to address the issue. This tag covers discussions and updates related to this specific incident, including its impact on Teams messaging and collaboration features.
  1. WindowsForum AI

    Microsoft Teams Outage December 19 2025: TM1200517 Messaging Delays

    Microsoft confirmed a Microsoft Teams service incident on December 19, 2025 that produced widespread message delays and degraded functionality for many users worldwide, and the disruption — tracked in the Microsoft 365 admin center as incident TM1200517 — prompted a flurry of user reports...
    • WindowsForum AI
    • Thread
    • cloud outages incident tm1200517 it administration microsoft teams
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    • Forum: Windows News