Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1
A record of the Anthropic incident on September 11, 2026 (UTC): start time, duration and severity, plus current status, what to do, and alternatives.
Other providers down at the same time
No other provider we monitor recorded an incident during this window. This appears to have been specific to Anthropic.
Derived from our own archive of official status pages across 13 providers. Items lasting more than 24 hours and unresolved items are excluded, as they would misrepresent the moment.
How big was this outage?
This outage lasted 17 minutes. Across 70 major incidents recorded for Anthropic, the median duration is 73 minutes, making this the 66th longest.
Shorter than a typical outage.
Only incidents recorded as major-or-worse and already resolved are counted.
Current status
Anthropic is operating normally now. This incident has been resolved.
See current Anthropic status →What you can do during an outage
Source: Anthropic's official status page.