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EU - Incident with Copilot GPT-5.1-Codex

Incident Report for GitHub Enterprise Cloud - EU

Resolved

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.
Posted Feb 20, 2026 - 11:41 UTC

Update

The issues with our upstream model provider have been resolved, and GPT 5.1 Codex is once again available in Copilot Chat and across IDE integrations [VSCode, Visual Studio, JetBrains].
We will continue monitoring to ensure stability, but mitigation is complete.
Posted Feb 20, 2026 - 11:19 UTC

Update

We are still experiencing degraded availability for the GPT 5.1 Codex model in Copilot Chat, VS Code and other Copilot products. This is due to an issue with an upstream model provider. We are working with them to resolve the issue.
Posted Feb 20, 2026 - 10:36 UTC

Update

We are experiencing degraded availability for the GPT 5.1 Codex model in Copilot Chat, VS Code and other Copilot products. This is due to an issue with an upstream model provider. We are working with them to resolve the issue.
Other models are available and working as expected.
Posted Feb 20, 2026 - 10:02 UTC

Investigating

We are investigating reports of degraded performance for Copilot
Posted Feb 20, 2026 - 10:02 UTC
This incident affected: Copilot.