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Anthropic · AISep 11, 2026, 14:19 UTC

Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1

MajorNot disclosedUpdated 21h ago
Sep 11, 14:19 UTCSep 11, 14:37 UTC
Duration
17m
Impact
Major
Root cause
Not disclosed
Anthropic, 90 days
94 incidents
Affected
claude.aiClaude API (api.anthropic.com)Claude CodeClaude Cowork
Status page

Final update

The issue affecting Claude services has been resolved. Impact occurred from 13:57 to 14:20 UTC

Timeline

  1. Resolved · Sep 11, 14:37 UTC
    The issue affecting Claude services has been resolved. Impact occurred from 13:57 to 14:20 UTC
  2. Monitoring · Sep 11, 14:28 UTC
    A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery.
  3. Monitoring · Sep 11, 14:28 UTC
    A fix has been deployed for Claude Mythos 5.1 and Claude Fable 5.1 and we are monitoring for recovery.
  4. Identified · Sep 11, 14:21 UTC
    We have identified the cause of elevated errors on requests to Claude Mythos 5.1 and Claude Fable 5.1 and are working on a fix. We will provide an update as soon as possible.
  5. Investigating · Sep 11, 14:19 UTC
    We are investigating elevated errors on requests to Claude Fable 5.1 and Claude Mythos 5.1. We will provide an update as soon as possible.

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Full history

From vendors' own status pages and disclosures. Times as reported. Logos via logo.dev; trademarks belong to their owners.

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