Elevated errors for Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5

Timeline

1. 23:37 UTC Claude status page · Reported Elevated errors for Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5
2. 23:37 UTC Claude status page · Investigating We are investigating elevated errors on requests to Claude Fable 5.1. We will provide an update as soon as possible.
3. 23:39 UTC Claude status page · Identified We have identified the cause of elevated errors on requests to Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5, as well as fast mode requests to Opus 5.5 and are working on a fix. We will provide an update as soon as possible.
4. 23:54 UTC Claude status page · Monitoring We are seeing success rates return to normal for all affected models, and are continuing to monitor to ensure no further issues.
5. 00:11 UTC Claude status page · Resolved The issue affecting Claude models has been resolved. Impact occurred from 16:28 PT / 23:28 UTC on October 23 to 16:59 PT / 23:59 UTC on October 23.