# GitHub Copilot: Major incident: Elevated errors on Fable 5 due to upstream provider

**Summary:** GitHub Copilot reported a major degradation affecting Claude Fable 5, with elevated errors and requests failing mid-response; no other models were impacted. The incident started at 2026-08-24 07:12 UTC and was resolved at 2026-08-24 07:58 UTC, lasting 46 min. An upstream provider issue caused the disruption, and the provider applied a mitigation. _(machine-written, sol)_
- Kind: Major incident · Label: degradation (model (Jev))
- Changed: 2026-08-24 07:12 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/4dz9rv14dz14](https://stspg.io/4dz9rv14dz14)
- [Company: GitHub Copilot](https://rewindex.com/company/github-copilot.md)
- Versions: before (none: first archived) → after incident\_version:18/wt3hjqcrczfg@478162490588
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Elevated errors on Fable 5 due to upstream provider
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ resolved
```

**4. Added: Start time**

```diff
+ 2026-08-24 07:12 UTC
```

**5. Added: Resolved time**

```diff
+ 2026-08-24 07:58 UTC
```

**6. Added: Affected components**

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

**7. Added: Update** (investigating) · 2026-08-24 07:12 UTC

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

**8. Added: Update** (investigating) · 2026-08-24 07:12 UTC

```diff
+ We are experiencing degraded availability for the Fable model in Copilot products and IDE surfaces. This is due to an issue with the upstream model provider. While we work with them to resolve the issue, we recommend choosing another model or selecting 'Auto' to continue using Copilot.
```

**9. Added: Update** (resolved) · 2026-08-24 07:58 UTC

```diff
+ On August 24th, 2026, between approximately 06:35 and 07:25 UTC, the Copilot service experienced a degradation of the Claude Fable 5 model due to an issue with our upstream provider. Users encountered elevated error rates when using Claude Fable 5, with requests sometimes failing mid-response. No other models were impacted.<br /><br />The issue was resolved by a mitigation put in place by our provider. GitHub is working with our provider to further improve the resiliency of the service to prevent similar incidents in the future.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2026-08-24 07:12 UTC | Major incident: Elevated errors on Fable 5 due to upstream provider (this change) | degradation |

All GitHub Copilot changes: [timeline](https://rewindex.com/company/github-copilot/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/i70df6d07841657 · Markdown: https://rewindex.com/change/i70df6d07841657.md · JSON: https://rewindex.com/api/v1/changes/i70df6d07841657 · Generated 2026-10-18T02:29:31.162Z