Claude Status · History · Incident #7149

RESOLVED

Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1

Major · Started Sep 11, 2026 · 2:19 PM

Duration

17m
Severity

Major
Detection lead

—
User reports

Peak 1/hr

Summary

Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1

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

Started

Sep 11, 2026 · 2:19 PM
Resolved

Sep 11, 2026 · 2:37 PM
Duration

17m
Severity

Major

Event timeline

How this incident unfolded

◐

Investigating
Sep 11 · 2:19 PM Claude

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.
◆

Identified
Sep 11 · 2:21 PM Claude

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.
◉

Monitoring
Sep 11 · 2:28 PM Claude

A fix has been deployed for Claude Mythos 5.1 and Claude Fable 5.1 and we are monitoring for recovery.
◉

Monitoring
Sep 11 · 2:28 PM Claude

A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery.
✓

Resolved
Sep 11 · 2:37 PM Claude

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

User reports · incident window

Report volume over time

Hourly report count. Red bars mark the incident window.

Peak: 1 reports/hr

← Before incident After →

Pattern

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