Outage in Anthropic
Intermittent error spikes for Claude Mythos 5.1 and Claude Fable 5.1
Resolved MajorIncident Report
Summary AI Generated
Claude Mythos 5.1 and Claude Fable 5.1 experienced intermittent error spikes affecting both claude.ai and api.anthropic.com for approximately 1.5 hours on September 15, 2026. The incident was classified as major, with elevated request errors impacting users across both platforms. A fix was deployed and confirmed resolved by 11:14 AM UTC.
We are investigating elevated errors on requests to Claude Mythos 5.1 and Claude Fable 5.1. We will provide an update as soon as possible.
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Latest Updates ( sorted recent to last )
RESOLVED
about 4 hours ago - at 09/15/2026 11:14AM
A fix has been deployed for Claude Mythos 5.1 and Claude Fable 5.1 and we are monitoring to ensure it has resolved the issue.
MONITORING
about 4 hours ago - at 09/15/2026 10:50AM
A fix has been deployed for Claude Mythos 5.1 and Claude Fable 5.1 and we are monitoring to ensure it has resolved the issue.
INVESTIGATING
about 5 hours ago - at 09/15/2026 09:52AM
We are investigating elevated errors on requests to Claude Mythos 5.1 and Claude Fable 5.1. We will provide an update as soon as possible.
INVESTIGATING
about 5 hours ago - at 09/15/2026 09:48AM
We are investigating elevated errors on requests to Claude Mythos 5.1 and Claude Fable 5.1. We will provide an update as soon as possible.
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