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

Bug Description
API Error: 400
{"type":"error","error":{"type":"invalid_request_error","message":"messages.7.content.1: 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_011CYeS4C4inVvYGERS6Vf2w"}

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.63
• Feedback ID: 7c9a325f-3657-4e0b-8e7f-7cd80b8312bd

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/kishore/.local/share/claude/versions/2.1.63 (expected in multi-process scenarios)\n    at sVR (/$bunfs/root/claude:2436:2100)\n    at QjA (/$bunfs/root/claude:2436:1211)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-02T14:44:23.309Z"},{"error":"Error: LSP server plugin:rust-analyzer-lsp:rust-analyzer crashed with exit code 1\n    at <anonymous> (/$bunfs/root/claude:2716:21470)\n    at emit (node:events:98:22)\n    at #handleOnExit (node:child_process:520:14)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-02T14:44:26.206Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.7.content.1: `thinking` or `redacted_thinking` blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.\"},\"request_id\":\"req_011CYeS3i4F8o9NJi4pR6RUR\"}\n    at generate (/$bunfs/root/claude:268:28476)\n    at makeRequest (/$bunfs/root/claude:307:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-02T14:44:38.977Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.7.content.1: `thinking` or `redacted_thinking` blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.\"},\"request_id\":\"req_011CYeS4C4inVvYGERS6Vf2w\"}\n    at generate (/$bunfs/root/claude:268:28476)\n    at makeRequest (/$bunfs/root/claude:307:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-02T14:44:44.926Z"}]