# Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1

- Provider: [Anthropic](https://down.guide/anthropic)
- Level: confirmed
- Impact: Partial outage
- lasted 17m
- started 2026-09-11 14:19 UTC
- claude.ai, Claude API (api.anthropic.com), Claude Code +1
- id: DWN-d059b784b3
- Official page: https://stspg.io/n9n8kfcxtkfm

## Updates from Anthropic
### 2026-09-11 14:19 UTC: investigating
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.

### 2026-09-11 14:21 UTC: identified
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.

### 2026-09-11 14:28 UTC: monitoring
A fix has been deployed for Claude Mythos 5.1 and Claude Fable 5.1 and we are monitoring for recovery.

### 2026-09-11 14:28 UTC: monitoring
A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery.

### 2026-09-11 14:37 UTC: resolved
The issue affecting Claude services has been resolved. Impact occurred from 13:57 to 14:20 UTC

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