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

Bug Description
API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"m
essages.41.content.33: 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_011CXVdoa7Fu481QaGkUw9wN"}

Environment Info

• Platform: win32
• Terminal: null
• Version: 2.1.19
• Feedback ID: 11121ad5-2951-485c-9046-9e677dbb0b1c

Errors

[{"error":"Error: ENOENT: no such file or directory, scandir 'C:\\ProgramData\\ClaudeCode\\.claude\\skills'\n    at readdirSync (unknown)\n    at <anonymous> (B:/~BUN/root/claude.exe:12:1903)\n    at cX (B:/~BUN/root/claude.exe:11:35427)\n    at readdirSync (B:/~BUN/root/claude.exe:12:1864)\n    at VJ$ (B:/~BUN/root/claude.exe:2213:380)\n    at VJ$ (B:/~BUN/root/claude.exe:2213:1350)\n    at <anonymous> (B:/~BUN/root/claude.exe:2213:4440)\n    at <anonymous> (B:/~BUN/root/claude.exe:2213:5171)\n    at A (B:/~BUN/root/claude.exe:11:7251)\n    at CTE (B:/~BUN/root/claude.exe:4860:4342)","timestamp":"2026-01-26T06:06:25.268Z"},{"error":"Error: ENOENT: no such file or directory, scandir 'C:\\Users\\tim\\.claude\\skills'\n    at readdirSync (unknown)\n    at <anonymous> (B:/~BUN/root/claude.exe:12:1903)\n    at cX (B:/~BUN/root/claude.exe:11:35427)\n    at readdirSync (B:/~BUN/root/claude.exe:12:1864)\n    at VJ$ (B:/~BUN/root/claude.exe:2213:380)\n    at VJ$ (B:/~BUN/root/claude.exe:2213:1350)\n    at <anonymous> (B:/~BUN/root/claude.exe:2213:4483)\n    at <anonymous> (B:/~BUN/root/claude.exe:2213:5171)\n    at A (B:/~BUN/root/claude.exe:11:7251)\n    at CTE (B:/~BUN/root/claude.exe:4860:4342)","timestamp":"2026-01-26T06:06:25.268Z"},{"error":"Error: EPERM: operation not permitted, symlink 'C:\\Users\\tim\\.claude\\projects\\D--Development-Claude-Web-Shaders\\117282a5-e44c-40fd-8fe1-9ae2d6d67de2\\subagents\\agent-af9d8ed.jsonl' -> 'C:\\Users\\tim\\AppData\\Local\\Temp\\claude\\D--Development-Claude-Web-Shaders\\tasks\\af9d8ed.output'\n    at symlinkSync (unknown)\n    at VPH (B:/~BUN/root/claude.exe:1724:1154)\n    at JtD (B:/~BUN/root/claude.exe:1733:1324)\n    at <anonymous> (B:/~BUN/root/claude.exe:2094:824)\n    at <anonymous> (B:/~BUN/root/claude.exe:2094:1638)\n    at run (node:async_hooks:62:22)\n    at WGH (B:/~BUN/root/claude.exe:633:98022)\n    at call (B:/~BUN/root/claude.exe:2094:520)\n    at async y9E (B:/~BUN/root/claude.exe:2961:20041)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-26T06:38:09.694Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.41.content.33: `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_011CXVdU7CUjRGkXN6m1nqmg\"}\n    at generate (B:/~BUN/root/claude.exe:143:37450)\n    at makeRequest (B:/~BUN/root/claude.exe:160:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-26T07:54:38.149Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.41.content.33: `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_011CXVdoa7Fu481QaGkUw9wN\"}\n    at generate (B:/~BUN/root/claude.exe:143:37450)\n    at makeRequest (B:/~BUN/root/claude.exe:160:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-26T07:59:01.969Z"}]