Claude Thinking Block Validation Error: Missing Required Thinking Block

[paulbettner]

Bug Description Thinking is causing this error frequently: API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.21.content.0.type: Expected thinking or redacted_thinking, but found text. When thinking is enabled, a final assistant message must start with a thinking block (preceeding the lastmost set of tool_use and tool_result blocks). We recommend you include thinking blocks from previous turns. To avoid this requirement, disable thinking. Please consult our documentation at https://docs.anthropic.com/en/docs/build-with-claude/extended-thinking"}}

Environment Info

• Platform: macos
• Terminal: vscode
• Version: 0.2.122
• Feedback ID: aae2bcc7-339d-4282-8970-24f4a269747d

Errors

[{"error":"Error: EISDIR: illegal operation on a directory, read\n    at Module.readSync (node:fs:742:18)\n    at Object.readSync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:499:901)\n    at eD (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:502:260)\n    at nB (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:504:358)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1807:1396\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)","timestamp":"2025-05-20T03:05:32.455Z"},{"error":"Error: EISDIR: illegal operation on a directory, read\n    at Module.readFileSync (node:fs:443:20)\n    at Object.readFileSync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:499:728)\n    at nB (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:504:376)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1807:1396\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)","timestamp":"2025-05-20T03:05:32.455Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at II (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:6010)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:5746\n    at Array.map (<anonymous>)\n    at Ob (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:5737)\n    at $e2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:9709)\n    at kw (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:91:19797)\n    at sM (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:42551)\n    at nM (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:38100)\n    at B$ (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:38028)\n    at tw (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:37882)","timestamp":"2025-05-20T03:06:10.689Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at II (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:6010)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:5746\n    at Array.map (<anonymous>)\n    at Ob (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:5737)\n    at $e2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1850:9709)\n    at kw (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:91:19797)\n    at sM (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:42551)\n    at nM (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:38100)\n    at B$ (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:38028)\n    at tw (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:37882)","timestamp":"2025-05-20T03:06:10.690Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: local\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1274:10912\n    at Object.useMemo (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:91:26270)\n    at _K4.useMemo (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:71:83971)\n    at UF (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1274:10806)\n    at kw (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:91:19797)\n    at sM (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:42551)\n    at nM (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:38100)\n    at B$ (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:38028)\n    at tw (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:93:37882)\n    at WV (file:///opt/homebrew/lib/node_mod

Note: Error logs were truncated.

[backnotprop]

duplicate of #1179