86 minutes
Claude’s two 5.1 models threw errors for 86 minutes on Tuesday morning
Anthropic’s status page opened an incident at 09:48 UTC on 15 September for “intermittent error spikes” on Claude Mythos 5.1 and Claude Fable 5.1.
A fix was posted at 10:50 and the incident closed at 11:14, 86 minutes after it opened. The page lists claude.ai, the API, Claude Code and Claude Cowork as affected and gives no cause a day later.
What it changes If retries fired in that window, it was them. There is nothing to change.
Primary source read
Intermittent error spikes for Claude Mythos 5.1 and Claude Fable 5.1