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

Bug Description
Began a goal prompt on auto mode, and it returns to me

"My tool calls (Bash, Read) are returning empty results this turn — even a plain echo hello came back with no output. This blocks the ARCHITECTURE.md refinement work. How would you like to proceed? → Retry now
⎿  API Error: 400 messages.3.content.7: 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: iTerm.app
• Version: 2.1.154
• Feedback ID: 23700d0a-e16e-4688-9b94-e3c4015ff7e3

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.3.content.7: `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_011CbVRY6381rDLbRbQ3D7PE\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:63816)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-28T18:15:59.089Z"}]