[Bug] Anthropic API Error: Cannot modify thinking blocks in assistant messages

Bug Description
⎿  API Error: 400 messages.319.content.12: thinking or redacted_thinking blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.153
• Feedback ID: c38bdc8d-2011-4754-8065-6a2b43ec882c

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.319.content.12: `thinking` or `redacted_thinking` blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.\"},\"request_id\":\"req_011CbVWaB8LxoYNqkipitb7T\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:63764)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-28T19:22:03.125Z"}]