Intermittent error spikes for Claude Mythos 5.1 and Claude Fable 5.1
A record of the Anthropic incident on September 15, 2026 (UTC): start time, duration and severity, plus current status, what to do, and alternatives.
Other providers down at the same time
2 other incident(s) at different providers overlapped with this one. It may not have been limited to a single service — several providers were degraded at once.
- ReplicateSome Replicate models are failing to start
- GitHubDisruption with some GitHub services
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 86 minutes. Across 57 major incidents recorded for Anthropic, the median duration is 86 minutes, making this the 30th longest.
About average in length.
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.
Other Anthropic incidents
- Issues with Google Play subscriptionsSeptember 16, 2026
- Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1September 11, 2026
- Elevated latency on the Claude API for some usersSeptember 10, 2026
- Degraded functionality for Claude Cowork on WindowsSeptember 10, 2026
- Elevated errors for multiple modelsSeptember 3, 2026