Incidentsby GlyphIncident with Copilot GPT-5.1-Codex
Feb 20, 10:02 UTCFeb 20, 11:41 UTC
Duration
1h 39m
Impact
Minor
Root cause
Not disclosed
GitHub, 90 days
69 incidents
Affected
Not listed by the vendor.
Final update
On February 20, 2026, between 07:30 UTC and 11:21 UTC, the Copilot service experienced a degradation of the GPT 5.1 Codex model. During this time period, users encountered a 4.5% error rate when using this model. No other models were impacted. The issue was resolved by a mitigation put in place by the external model provider. GitHub is working with the external model provider to further improve the resiliency of the service to prevent similar incidents in the future.
Timeline
- Resolved · Feb 20, 11:41 UTC
On February 20, 2026, between 07:30 UTC and 11:21 UTC, the Copilot service experienced a degradation of the GPT 5.1 Codex model. During this time period, users encountered a 4.5% error rate when using this model. No other models were impacted. The issue was resolved by a mitigation put in place by the external model provider. GitHub is working with the external model provider to further improve the resiliency of the service to prevent similar incidents in the future.