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Claude: Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1

Impact: majorStatus: resolvedStarted Resolved (16 min)2 updatesSource: stspg.io (opens in new tab)
Summary

Claude reported major elevated errors for Claude Mythos 5.1 and Claude Fable 5.1 across claude.ai, Claude API (api.anthropic.com), Claude Code and Claude Cowork. The incident started at 2026-10-05 13:05 UTC and resolved at 2026-10-05 13:21 UTC (computed duration: 15 min); the vendor separately stated an impact window of 12:40 UTC to 13:10 UTC.

Machine-written from the archived incident (Sol). Check the timeline before relying on it.

Affected components: Claude CoworkClaude API (api.anthropic.com)claude.aiClaude Code

Timeline of updates

  1. investigating

    We are investigating elevated errors on requests to Claude Mythos 5.1 and Claude Fable 5.1. We will provide an update as soon as possible.

  2. resolved

    The issue affecting Claude Mythos 5.1 and Claude Fable 5.1 has been resolved. Impact occurred from 05:40 PT / 12:40 UTC to 06:10 PT / 13:10 UTC.

Rewindex changes for this incident

Impact, status and times are the vendor’s own, as last archived. View on stspg.io (opens in new tab). Claude profile · Recent Claude incidents · Markdown · JSON