Fix: Next.js Environment Variables Returning undefined
How to fix Next.js environment variables returning undefined — NEXT_PUBLIC prefix rules, server vs client context, .env file loading order, and runtime vs build-time variable access.
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836 articles — Page 49 of 70
Fix: Python asyncio Not Running / async Functions Not Executing
How to fix Python asyncio not running — coroutines never executing, RuntimeError no running event loop, mixing sync and async code, and common async/await mistakes in Python.
Fix: React.lazy and Suspense Errors (Element Type Invalid, Loading Chunk Failed)
How to fix React.lazy and Suspense errors — Element type is invalid, A React component suspended while rendering, Loading chunk failed, and lazy import mistakes with named vs default exports.
Fix: TypeScript Path Aliases Not Working (Cannot Find Module '@/...')
How to fix TypeScript path aliases not resolving — tsconfig paths configured but imports still fail at runtime, in Jest, or after building with webpack, Vite, or ts-node.
Fix: Webpack HMR (Hot Module Replacement) Not Working
How to fix Webpack Hot Module Replacement not updating the browser — HMR connection lost, full page reloads instead of hot updates, and HMR breaking in Docker or behind a proxy.
Fix: CSS Flexbox Not Working (display: flex Has No Effect)
How to fix CSS Flexbox not working — why display flex has no effect, flex children not aligning, flex-grow not stretching, and how to debug common Flexbox layout issues.
Fix: git fatal: A branch named 'x' already exists
How to fix 'git fatal: A branch named already exists' when creating or renaming branches — including local conflicts, remote tracking branches, and worktree issues.
Fix: UnhandledPromiseRejectionWarning / UnhandledPromiseRejection
How to fix UnhandledPromiseRejectionWarning in Node.js and unhandled promise rejection errors in JavaScript caused by missing catch handlers, async/await mistakes, and event emitter errors.
Fix: Jest Timeout — Exceeded timeout of 5000ms for a test
How to fix Jest 'Exceeded timeout of 5000ms for a test' errors caused by unresolved promises, missing done callbacks, async/await mistakes, and slow database or network calls in tests.
Fix: sudo: command not found on Linux
How to fix 'sudo: command not found' on Linux — caused by sudo not installed, missing PATH in scripts, Docker containers without sudo, and su vs sudo confusion on minimal systems.
Fix: Nginx location Block Not Matching (Wrong Route Served)
How to fix Nginx location blocks not matching — caused by prefix vs regex priority, trailing slash issues, root vs alias confusion, and try_files misconfiguration.
Fix: Python SSL: CERTIFICATE_VERIFY_FAILED
How to fix Python SSL CERTIFICATE_VERIFY_FAILED error caused by missing root certificates on macOS, expired system certs, corporate proxies, and self-signed certificates in requests, urllib, and httpx.