Elevated error rates on Opus 4.6

Incident update

On March 26–27, 2026, customers experienced elevated error rates when using Claude Opus 4.6 and Claude Sonnet 4.6. The issue was caused by a networking performance degradation within our infrastructure that disrupted communication between components of our serving stack. We resolved the incident by migrating the affected workloads to healthy infrastructure, restoring normal service by 9:30 AM PT on March 27.