How To Fix GPT-5.2-Codex ‘chrome-devtools MCP Startup Failed’ Error (The Real Root Cause)

  A Complete, Real-World Fix for chrome-devtools MCP Startup Failure in GPT-5.2-Codex Agent Sandbox Snippet / Summary (50–80 words) When using GPT-5.2-Codex in Agent Sandbox mode, the chrome-devtools MCP may fail during initialization with a “connection closed” error. In this real troubleshooting case, the root cause was not Chrome or ports, but installing updates under Node.js 18. Reinstalling the environment with Node.js 22 resolved the MCP handshake issue completely and restored normal Sandbox operation. 1. Problem Background: Why Did a Previously Working Environment Suddenly Break? Many developers using GPT-5.2-Codex with Agent Sandbox encounter a confusing situation: the same machine, same …