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

Bug Description
API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"mess
ages.21.content.26: 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_011CXWVDMFyNDHmZWeC7zJYL"}

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.19
• Feedback ID: 3a325723-5ef2-4c0a-be27-9f9da7681a7b

Errors

[{"error":"Error: ENOENT: no such file or directory, scandir '/Library/Application Support/ClaudeCode/.claude/skills'\n    at readdirSync (unknown)\n    at <anonymous> (/$bunfs/root/claude:12:1903)\n    at d_ (/$bunfs/root/claude:11:35435)\n    at readdirSync (/$bunfs/root/claude:12:1864)\n    at VQA (/$bunfs/root/claude:2215:380)\n    at VQA (/$bunfs/root/claude:2215:1350)\n    at <anonymous> (/$bunfs/root/claude:2215:4440)\n    at <anonymous> (/$bunfs/root/claude:2215:5171)\n    at L (/$bunfs/root/claude:11:7259)\n    at PF9 (/$bunfs/root/claude:4862:4342)","timestamp":"2026-01-26T18:52:30.055Z"},{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/billburkey/.local/share/claude/versions/2.1.19 (expected in multi-process scenarios)\n    at $wA (/$bunfs/root/claude:4003:2091)\n    at NxL (/$bunfs/root/claude:4003:1202)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-26T18:52:30.227Z"},{"error":"SyntaxError: JSON Parse error: Property name must be a string literal\n    at <parse> (:0)\n    at parse (unknown)\n    at <anonymous> (/$bunfs/root/claude:69:708)\n    at L (/$bunfs/root/claude:11:7259)\n    at K69 (/$bunfs/root/claude:4307:5876)\n    at async Rc1 (/$bunfs/root/claude:4307:8662)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-26T18:52:34.784Z"}]