---
id: "INC-anthropic-h101vcmhnfky"
kind: "incident"
aliases: []
title: "Anthropic: Elevated errors for Claude Fable 5.1"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "resolved"
category: "vendor"
products: [{"name": "Anthropic", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ai", "anthropic", "incident", "llm", "ops", "vendor"]
not_affected_if: []
published_at: "2026-10-23T23:37:42+00:00"
first_seen_at: "2026-10-23T23:38:48+00:00"
updated_at: "2026-10-25T04:51:22+00:00"
sources: [{"source": "statuspage", "url": "https://stspg.io/gqp288t3qzpt", "first_seen_at": "2026-10-23T23:38:48+00:00"}]
---

# Anthropic: Elevated errors for Claude Fable 5.1

## Affected

- vendor:Anthropic affected ? fixed ?

## Timeline

- 2026-10-23T23:38:48+00:00 statuspage https://stspg.io/gqp288t3qzpt

## From the sources

We have identified the cause of elevated errors on requests to Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5, as well as fast mode requests to Opus 5.5 and are working on a fix. We will provide an update as soon as possible.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_