[BUG] in Claude code Desktop - model Opus 4.6

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Code desktop, model Opus 4.6 on windows. I get:
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9FwoGJS3SA2ekedfJs3"}

Appeared around 22:00 IL time
Works with Sonnet 4.6

What Should Happen?

Work as usual with Sonnet model

Error Messages/Logs

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9FwoGJS3SA2ekedfJs3"}

Steps to Reproduce

try working with Opus 4.6 module on Claude Desktop on windows

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

1.1.6...

Claude Code Version

Claude 1.1.7053 (cc1949) 2026-03-16T22:55:50.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_