How to Read Error Messages

Error messages are the biggest source of frustration for vibe coders. Here are the most common errors and what they mean:

Frontend Errors

Error	Meaning	Fix
Cannot read properties of undefined	Data hasn’t loaded yet	Add a loading check: if (data) { ... }
Module not found	Import path is wrong or package missing	Check path typos; run npm install
Hydration mismatch	Server HTML differs from client render	Common in Next.js; usually browser extensions or server/client code mismatch
Too many re-renders	Infinite update loop	State update is in component body, not in event handler

Backend and Build Errors

Error	Meaning	Fix
ECONNREFUSED	Cannot connect to database or service	Check connection URL and that service is running
Port already in use	Another process uses that port	Kill the other process or change port
CORS error	Browser blocked cross-domain request	Configure CORS headers on backend
npm ERR! peer dep	Package version conflicts	Try npm install --legacy-peer-deps

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🔑 The Golden Rule

Read the FIRST line of the error carefully. Copy it into Google or your AI tool. 90% of errors have been encountered and solved by others before you.

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