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

Bug Description
API Error: 400 messages.3.content.4: 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: linux
• Terminal: vte-based
• Version: 2.1.154
• Feedback ID: 366bcc88-e710-4881-be39-27a21fff5a00

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.4: `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_011CbVVECRonQKVgeidhDvxF\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:63571)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-28T19:04:23.223Z"}]