[BUG] API Error 500 on all prompts including /feedback command - Sonnet 4.5 and Opus 4.5

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 CLI returns API Error 500 on every single prompt, including system commands like /feedback. Complete inability to use Claude Code.

Error message:
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CXmP4Qsci57hDQdqh3MLp"}

Additional request IDs:

• req_011CXmPt4mUMXok6C4NZMFgG (when trying /feedback command)

What Should Happen?

Claude Code should accept prompts and execute commands normally. The /feedback command should open a feedback form.

Bug Description
API Error 500 on ALL prompts including /feedback command

Error:
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CXmP4Qsci57hDQdqh3MLp"}

Environment:

• Platform: Windows
• Terminal: PowerShell
• Version: 2.1.29
• Model: claude-opus-4-5 (Sonnet 4.5 also fails)
• Date: February 3, 2026, ~12:00 PM Mexico City time

What I tried:

• claude update → already on latest (2.1.29)
• claude auth logout/login → tried 2 times
• Restarted Claude Code multiple times
• Even claude feedback command returns 500 error

Usage limits checked:

• Current week (Sonnet): 3% used ✓
• Have available quota ✓

Impact:
Complete inability to use Claude Code CLI. Cannot send feedback, cannot execute any prompts.

Related issues:
Similar reports: #20177, #21443, #19166, #21445

Error Messages/Logs

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CXmP4Qsci57hDQdqh3MLp"}

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CXmPt4mUMXok6C4NZMFgG"}

Steps to Reproduce

1. Open PowerShell terminal
2. Navigate to project directory: C:\Users\abela\prweb\web26-602-shopify-woocommerce-link
3. Run: claude
4. Type any prompt (e.g., "hello")
5. Observe API Error 500
6. Try: /feedback
7. Observe same API Error 500

Note: Issue persists after:

• Running claude auth logout/login (tried 2 times)
• Restarting terminal multiple times
• Closing and reopening Claude Code
• Verifying latest version with claude update

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

until February 3, 2026 around 940 AM Mexico City time

Claude Code Version

2.1.29

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• Verified usage limits: Only 3% Sonnet usage for the week - well under limits
• Located in San Luis Potosí, Mexico
• Issue started suddenly on Feb 3, 2026
• claude.ai web interface works normally
• Related issues: #20177 (20 users affected), #21443, #19166, #21445

This appears to be a server-side issue affecting multiple users simultaneously.