# GitHub: Incident with Copilot

- Impact (vendor’s label): major
- Status: resolved
- Started: 2025-11-28 06:59 UTC · Resolved: 2025-11-28 08:23 UTC · Duration: 1.4 h
- Updates: 1
- [Vendor status page: https://www.githubstatus.com/incidents/d4775b3j5mwm](https://www.githubstatus.com/incidents/d4775b3j5mwm)
- [Company: GitHub](https://rewindex.com/company/github.md)

## Timeline of updates

- **resolved** 2025-11-28 08:23 UTC: On November 28th, 2025, between approximately 05:51 and 08:04 UTC, Copilot experienced an outage affecting the Claude Sonnet 4.5 model. Users attempting to use this model received an HTTP 400 error, resulting in 4.6% of total chat requests during this timeframe failing. Other models were not impacted. The issue was caused by a misconfiguration deployed to an internal service which made Claude Sonnet 4.5 unavailable. The problem was identified and mitigated by reverting the change. GitHub is working to improve cross-service deploy safeguards and monitoring to prevent similar incidents in the future.

_From the vendor’s published history: only the final update text is available for incidents before Rewindex began polling this page._


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Canonical: https://rewindex.com/company/github/incidents/d4775b3j5mwm · Markdown: https://rewindex.com/company/github/incidents/d4775b3j5mwm.md · JSON: https://rewindex.com/api/v1/companies/github/incidents/d4775b3j5mwm · Generated 2026-10-18T09:34:36.349Z