# GitHub: Major incident: Degradation with Gemini 3.8 Flash

**Summary:** GitHub reported a major Gemini 3.8 Flash degradation in Copilot starting 2026-09-16 07:20 UTC, resolved at 2026-09-16 17:48 UTC (10 h 27 min). Requests failed at an average rate of 6.4% due to a capacity issue; mitigation was reported at 11:45 UTC. Other models were unaffected; users could switch models or use 'Auto'. _(machine-written, sol)_
- Kind: Major incident · Label: degradation (model (Jev))
- Changed: 2026-09-16 07:20 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/hsjy12f57b24](https://stspg.io/hsjy12f57b24)
- [Company: GitHub](https://rewindex.com/company/github.md)
- Versions: before (none: first archived) → after incident\_version:187/nlxnbqnkdzdl@2fb4b330bb74
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Degradation with Gemini 3.8 Flash
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ resolved
```

**4. Added: Start time**

```diff
+ 2026-09-16 07:20 UTC
```

**5. Added: Resolved time**

```diff
+ 2026-09-16 17:48 UTC
```

**6. Added: Affected components**

```diff
+ Copilot AI Model Providers
```

**7. Added: Update** (investigating) · 2026-09-16 07:21 UTC

```diff
+ We are investigating reports of degraded availability for Copilot AI Model Providers
```

**8. Added: Update** (investigating) · 2026-09-16 08:28 UTC

```diff
+ Copilot AI Model Providers is experiencing degraded performance. We are continuing to investigate.
```

**9. Added: Update** (investigating) · 2026-09-16 10:58 UTC

```diff
+ Copilot AI Model Providers is experiencing degraded performance. We are continuing to investigate.
```

**10. Added: Update** (monitoring) · 2026-09-16 11:45 UTC

```diff
+ The degradation affecting Copilot AI Model Providers has been mitigated. We are monitoring to ensure stability.
```

**11. Added: Update** (resolved) · 2026-09-16 17:48 UTC

```diff
+ On September 16, 2026, between 04:40 and 11:45 UTC, the Gemini 3.8 Flash model in GitHub Copilot experienced degraded availability. Requests to this model failed at an average rate of 6.4%, and the impact was highest during peak traffic hours. Other Copilot models were not affected. Users could continue to work with a different model or with 'Auto'.<br /><br />The degradation was caused due to a capacity issue with an upstream model provider. Failure rates returned to normal as the daily traffic peak passed. We monitored the model until it was healthy and resolved the incident at 17:48 UTC. We are working to make our systems resilient to cover peak demand for all the Copilot models.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2026-09-16 07:20 UTC | Major incident: Degradation with Gemini 3.8 Flash (this change) | degradation |

All GitHub changes: [timeline](https://rewindex.com/company/github/changes.md)
_Diff excerpts are shown on normalized text: dates, counters and tokens appear as ‹date›, ‹count›, ‹tok›; noise-only edits are hidden. Rewindex shows the changed passages, not a copy of the page._


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Canonical: https://rewindex.com/change/i39f8e4c35fce84 · Markdown: https://rewindex.com/change/i39f8e4c35fce84.md · JSON: https://rewindex.com/api/v1/changes/i39f8e4c35fce84 · Generated 2026-10-18T02:29:19.060Z