Anthropic change history: Elevated errors for Claude Opus 5.5

Claude Opus 5.5 requests experienced elevated errors affecting claude.ai, Claude API (api.anthropic.com), Claude Code, and Claude Cowork. Anthropic rated the impact major; the incident started at 2026-10-06 12:24 UTC and was resolved at 2026-10-06 12:43 UTC, lasting 18 min. Anthropic identified the cause but did not disclose it or the fix.