Anthropic reported that requests to Claude Fable 5, Claude Fable 5.1, Claude Mythos 5, and Claude Mythos 5.1 have returned to normal success rates following an incident of elevated errors. The company stated it is still working to resolve remaining errors affecting Claude Opus 5. The incident, identified on Sep 22, 2026, affected claude.ai, the Claude API, Claude Code, and Claude Cowork. Anthropic said it would provide an additional update shortly.
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