[Bug] Anthropic API Error 400 during extended thinking with MCP tools

Bug Description
API Error 400 during sequential thinking (MCP) usage

Environment Info

• Platform: win32
• Terminal: vscode
• Version: 2.1.17
• Feedback ID: 2328c5f3-ea6b-4d83-9e72-7f373a1f1e69

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 kX (B:/~BUN/root/claude.exe:11:35097)\n    at readdirSync (B:/~BUN/root/claude.exe:12:1864)\n    at wF$ (B:/~BUN/root/claude.exe:1477:380)\n    at wF$ (B:/~BUN/root/claude.exe:1477:1350)\n    at <anonymous> (B:/~BUN/root/claude.exe:1477:4440)\n    at <anonymous> (B:/~BUN/root/claude.exe:1477:5171)\n    at A (B:/~BUN/root/claude.exe:11:7244)\n    at c7E (B:/~BUN/root/claude.exe:4782:4342)","timestamp":"2026-01-23T11:12:17.636Z"},{"error":"Error: LSP server plugin:typescript-lsp:typescript failed to start: ENOENT: no such file or directory, uv_spawn 'typescript-language-server'\n    at start (B:/~BUN/root/claude.exe:1547:22097)\n    at async E (B:/~BUN/root/claude.exe:1547:24549)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-23T11:12:19.053Z"},{"error":"Error: ENOENT: no such file or directory, uv_spawn 'typescript-language-server'\n    at spawn (unknown)\n    at spawn (node:child_process:679:35)\n    at spawn (node:child_process:14:39)\n    at start (B:/~BUN/root/claude.exe:1547:20642)\n    at start (B:/~BUN/root/claude.exe:1547:22151)\n    at E (B:/~BUN/root/claude.exe:1547:24549)\n    at E (B:/~BUN/root/claude.exe:1547:25524)\n    at L (B:/~BUN/root/claude.exe:1547:32311)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-23T11:12:19.054Z"},{"error":"Error: Failed to start LSP server plugin:typescript-lsp:typescript: ENOENT: no such file or directory, uv_spawn 'typescript-language-server'\n    at <anonymous> (B:/~BUN/root/claude.exe:1547:32333)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-23T11:12:19.054Z"},{"error":"Error: Error opening file C:\\Users\\micha\\.claude\\projects\\C--Users-micha-OneDrive-Desktop-ClaudeProjects-LektoratAddin\\88fa991c-a9cc-43d2-a415-4697b8d3bddd.jsonl: Error: ENOENT: no such file or directory, open 'C:\\Users\\micha\\.claude\\projects\\C--Users-micha-OneDrive-Desktop-ClaudeProjects-LektoratAddin\\88fa991c-a9cc-43d2-a415-4697b8d3bddd.jsonl'\n    at aj (B:/~BUN/root/claude.exe:69:175)\n    at async p7H (B:/~BUN/root/claude.exe:3816:2075)\n    at async RYI (B:/~BUN/root/claude.exe:3817:638)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-23T11:12:36.581Z"},{"error":"Error: EPERM: operation not permitted, symlink 'C:\\Users\\micha\\.claude\\projects\\C--Users-micha-OneDrive-Desktop-ClaudeProjects-LektoratAddin\\ef16e8be-3b38-4339-a0a3-44e339b0afd9\\subagents\\agent-a081678.jsonl' -> 'C:\\Users\\micha\\AppData\\Local\\Temp\\claude\\C--Users-micha-OneDrive-Desktop-ClaudeProjects-LektoratAddin\\tasks\\a081678.output'\n    at symlinkSync (unknown)\n    at z4H (B:/~BUN/root/claude.exe:1473:9976)\n    at LeD (B:/~BUN/root/claude.exe:2213:1324)\n    at <anonymous> (B:/~BUN/root/claude.exe:2953:818)\n    at <anonymous> (B:/~BUN/root/claude.exe:2953:1628)\n    at run (node:async_hooks:62:22)\n    at dBH (B:/~BUN/root/claude.exe:352:32232)\n    at call (B:/~BUN/root/claude.exe:2953:515)\n    at async k$E (B:/~BUN/root/claude.exe:3023:19033)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-23T11:14:44.658Z"},{"error":"Error: EPERM: operation not permitted, symlink 'C:\\Users\\micha\\.claude\\projects\\C--Users-micha-OneDrive-Desktop-ClaudeProjects-LektoratAddin\\ef16e8be-3b38-4339-a0a3-44e339b0afd9\\subagents\\agent-ae4be0e.jsonl' -> 'C:\\Users\\micha\\AppData\\Local\\Temp\\claude\\C--Users-micha-OneDrive-Desktop-ClaudeProjects-LektoratAddin\\tasks\\ae4be0e.output'\n    at symlinkSync (unknown)\n    at z4H (B:/~BUN/root/claude.exe:1473:9976)\n    at LeD (B:/~BUN/root/claude.exe:2213:1324)\n    at <anonymous> (B:/~BUN/root/claude.exe:2953:818)\n    at <anonymous> (B:/~BUN/root/claude.exe:2953:1628)\n    at run (node:async_hooks:62:22)\n    at dBH (B:/~BUN/root/claude.exe:352:32232)\n    at call (B:/~BUN/root/claude.exe:2953:515)\n    at async k$E (B:/~BUN/root/claude.exe:3023:19033)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-23T11:14:44.701Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.7.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_011CXQDXSuezxiYNBTVPi856\"}\n    at generate (B:/~BUN/root/claude.exe:143:37450)\n    at makeRequest (B:/~BUN/root/claude.exe:160:5435)…

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