JavaScript & React Error Guides

React Mar 8, 2026 New

React Error #418: Hydration failed — server & client mismatch

Why hydration fails in Next.js with window APIs and dynamic dates, fixed with useEffect and dynamic().

Read article

React Mar 8, 2026 New

React Error #185: Maximum update depth exceeded — Fixed

Infinite render loops from setState in render bodies and cyclic useEffect dependencies — with the exact fix for each pattern.

Read article

React Mar 8, 2026 New

React Error #310: Minified React error in production — Fixed

How to decode minified React errors and why #310 (Objects are not valid as a React child) happens — with 3 code fixes.

Read article

React Mar 8, 2026 New

How to Create a React Error Boundary Component in 2026

The modern way using react-error-boundary — no class components, includes auto-reset on navigation and Sentry logging.

Read article

JavaScript Mar 8, 2026

JavaScript TypeError: Cannot read properties of undefined — Fixed

Why this happens with async data and nested objects, and how Optional Chaining fixes it instantly.

Read article

JavaScript Mar 8, 2026

ReferenceError: Cannot access before initialization (TDZ) — Fixed

The Temporal Dead Zone with let/const explained — why var hides this bug and how to fix it.

Read article