Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1

Anthropic resolved elevated error rates on requests to Claude Mythos 5.1 and Claude Fable 5.1, with impact lasting from 13:57 to 14:20 UTC on September 11, according to the company's status updates. Anthropic identified the cause at 14:21 UTC, deployed a fix at 14:28 UTC, and confirmed resolution at 14:37 UTC.

Sep 11 , 14:37 UTC Resolved - The issue affecting Claude services has been resolved. Impact occurred from 13:57 to 14:20 UTC Sep 11 , 14:28 UTC Update - A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery. Sep 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. Sep 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. Sep 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.