# Claude: Major incident: Elevated errors for Claude Opus 5.5

**Summary:** Claude reported a major incident involving elevated errors for Claude Opus 5.5 across claude.ai, Claude API (api.anthropic.com), Claude Code, and Claude Cowork. It started at 2026-10-06 12:24 UTC and was resolved at 2026-10-06 12:43 UTC, lasting 18 min. Claude said it identified the cause but did not disclose the cause or fix. _(machine-written, sol)_
- Kind: Major incident · Label: outage (model (Jev))
- Changed: 2026-10-06 12:24 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/bzc81gbv1b99](https://stspg.io/bzc81gbv1b99)
- [Company: Claude](https://rewindex.com/company/claude.md)
- Versions: before (none: first archived) → after incident\_version:6/ch27pb90bn85@ef2f5506c4c8
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Elevated errors for Claude Opus 5.5
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ resolved
```

**4. Added: Start time**

```diff
+ 2026-10-06 12:24 UTC
```

**5. Added: Resolved time**

```diff
+ 2026-10-06 12:43 UTC
```

**6. Added: Affected components**

```diff
+ claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork
```

**7. Added: Update** (investigating) · 2026-10-06 12:24 UTC

```diff
+ We are investigating elevated errors on requests to Claude Opus 5.5. We will provide an update as soon as possible.
```

**8. Added: Update** (identified) · 2026-10-06 12:37 UTC

```diff
+ We have identified the cause of elevated errors on requests to Claude Opus 5.5 and are working on a fix. We will provide an update as soon as possible.
```

**9. Added: Update** (resolved) · 2026-10-06 12:43 UTC

```diff
+ The issue affecting Claude Opus 5.5 has been resolved.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2026-10-06 12:24 UTC | Major incident: Elevated errors for Claude Opus 5.5 (this change) | outage |

All Claude changes: [timeline](https://rewindex.com/company/claude/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/i1e447a5fb7e482 · Markdown: https://rewindex.com/change/i1e447a5fb7e482.md · JSON: https://rewindex.com/api/v1/changes/i1e447a5fb7e482 · Generated 2026-10-18T02:31:28.209Z