Updated 9:50 a.m. Eastern on September 3, 2026
Claude has identified the cause of elevated errors affecting requests to several models and is working on a fix. The incident is marked as major and ongoing.
What is affected
The incident affects requests to Claude Mythos 5.1, Claude Fable 5.1, Claude Opus 5, and also Mythos/Fable 5, Opus 4.8, and Opus 4.6. Components impacted include claude.ai, Claude API, Claude Code, and Claude Cowork.
Official update timeline
We are investigating elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5. We will provide an update as soon as possible.
We have identified the cause of elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and are working on a fix. We will provide an update as soon as possible.
An exhaustive list of affected models: Mythos/Fable 5.1, Mythos/Fable 5, Opus 5, Opus 4.8, Opus 4.6.
