40 articles
RSSFix Next.js 15 async cookies() and headers() errors — 'Route used cookies', 'Cookies can only be modified in a Server Action or Route Handler', codemod misses, library compatibility, and TypeScript type mismatches after upgrade.
How to fix next-themes errors — hydration mismatch on mount, FOUC flash before theme applies, Tailwind dark: classes not switching, ThemeProvider in App Router, defaultTheme system not respected, and TypeScript types.
How to fix React 19 actions errors — useActionState signature, form action vs onSubmit, useFormStatus must be in child, useOptimistic state desync, Server Actions in client components, and error handling.
How to fix Sentry source maps errors — minified stack traces, release name mismatch between build and runtime, sentry-cli upload-sourcemaps options, Vite/Webpack/Next.js plugin setup, and hiding maps from public.
How to fix Vercel Blob errors — BLOB_READ_WRITE_TOKEN missing, put vs handleUpload for browser, public vs private access, multipart upload for large files, expires/signed URLs, list/cursor pagination, and overwriting URLs.
How to fix Vercel Edge Function errors — Node.js APIs not available in Edge Runtime, 1MB bundle size limit, Postgres/MySQL drivers incompatible, streaming responses, geo headers, and Middleware vs Edge API Route.
How to fix Next.js 15 async params and searchParams errors — await in Server Components, React.use in Client Components, generateMetadata, generateStaticParams, and the codemod migration path.
How to fix React Compiler issues — eslint-plugin-react-compiler not flagging, babel-plugin-react-compiler not running, 'Function contains a code construct that prevents compilation', Next.js 15 config, and removing useMemo/useCallback safely.
How to fix SWR errors — useSWR not refetching on key change, mutate not invalidating, conditional null key, fallbackData vs fallback, SSR hydration mismatch, infinite scroll pagination, and TypeScript typing.
How to fix Algolia issues — indexing, search queries, InstantSearch setup, ranking configuration, facets, API key permissions, and Next.js integration.
How to fix Chakra UI v3 issues — ChakraProvider setup, color mode, theming, server-side rendering in Next.js, component styling, and common runtime errors.
How to fix Sanity CMS issues — GROQ queries, CORS configuration, dataset permissions, image URLs, Portable Text, webhooks, and Next.js integration.
How to fix UploadThing issues — file router configuration, Next.js App Router and Pages Router setup, CORS, file type restrictions, progress callbacks, and deployment.
How to fix Clerk authentication issues — ClerkProvider setup, middleware configuration, useUser and useAuth hooks, server-side auth, webhook handling, and organization features.
How to fix Contentlayer and Contentlayer2 issues — content source configuration, document type definitions, MDX processing, computed fields, Next.js integration, and migration to alternatives.
How to fix Fumadocs documentation framework issues — Next.js App Router setup, content source configuration, sidebar generation, MDX components, search, OpenAPI integration, and custom themes.
How to fix next-safe-action issues — action client setup, Zod schema validation, useAction and useOptimisticAction hooks, middleware, error handling, and authorization patterns.
How to fix Nextra documentation site issues — Next.js integration, _meta.json sidebar configuration, custom MDX components, search setup, theme customization, and static export.
How to fix nuqs URL search params state management — useQueryState and useQueryStates setup, parsers, server-side access, shallow routing, history mode, and Next.js App Router integration.
How to fix Vercel AI SDK issues — useChat and useCompletion hooks, streaming responses with streamText, provider configuration for OpenAI and Anthropic, tool calling, and Next.js integration.
How to fix NextAuth.js (Auth.js) issues — session undefined in server components, OAuth callback URL mismatch, JWT vs database sessions, middleware protection, and credentials provider.
How to fix Next.js Server Actions — use server directive, form binding, revalidation, error handling, middleware conflicts, and client component limitations.
How to fix Next.js font loading issues — next/font/google setup, CSS variable approach, local fonts, font-display settings, FOUT flash, and Tailwind CSS font integration.
How to fix React hydration errors — server/client HTML mismatches, useEffect for client-only code, suppressHydrationWarning, dynamic content, and Next.js specific hydration issues.
How to fix Next.js App Router fetch caching issues — understanding cache behavior, revalidation with next.revalidate, opting out with no-store, cache tags, and debugging stale data.
How to fix React Server Components errors — useState and hooks in server components, missing 'use client' directive, async component patterns, serialization errors, and client/server boundary mistakes.
How to fix CORS errors in Next.js API routes — adding Access-Control headers, handling preflight OPTIONS requests, configuring next.config.js headers, and avoiding common proxy mistakes.
How to fix Next.js middleware not executing — wrong file location, matcher config errors, middleware not intercepting API routes, and how to debug middleware execution in Next.js 13 and 14.
How to fix Next.js build failures — TypeScript errors blocking production builds, module resolution failures, missing environment variables, static generation errors, and common next build crash causes.
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.
How to fix the Next.js 500 Internal Server Error by checking server logs, fixing getServerSideProps, API routes, environment variables, database connections, middleware, and deployment issues.
How to fix Next.js API route 404 not found errors caused by wrong file paths, App Router vs Pages Router confusion, incorrect exports, and deployment issues.
How to fix Next.js Module not found Can't resolve fs error caused by importing Node.js modules in client components, wrong server/client boundaries, and missing polyfills.
How to fix Next.js Image component errors including 'Invalid src prop', 'hostname not configured', missing loader, and optimization failures in production.
How to fix useEffect infinite loops in React — covers missing dependency arrays, referential equality, useCallback, unconditional setState, data fetching cleanup, event listeners, useRef, previous value comparison, and the exhaustive-deps lint rule.
How to fix the Next.js hydration mismatch error. Covers invalid HTML nesting, browser extensions, Date/time differences, useEffect for client-only code, dynamic imports, suppressHydrationWarning, localStorage, third-party scripts, Math.random, auth state, and React portals.
How to fix 'Loading chunk failed', 'ChunkLoadError', and 'Failed to fetch dynamically imported module' in webpack, Next.js, React, and Vite. Covers stale deployments, CDN caching, publicPath misconfiguration, service worker cache, code splitting, dynamic import retry strategies, React.lazy error boundaries, and Next.js-specific solutions.
How to fix 'ERR_CONNECTION_REFUSED', 'localhost refused to connect', and 'This site can't be reached' errors when accessing localhost in Chrome, Firefox, and Edge. Covers dev servers, port issues, 0.0.0.0 vs 127.0.0.1, Docker port mapping, WSL2, firewalls, and more.
How to fix 'process.env.VARIABLE_NAME is undefined' and environment variables not loading from .env files in Node.js, React, Next.js, Vite, and Docker.
How to fix 'port 3000 is already in use', 'EADDRINUSE', and 'address already in use :::3000' errors in Node.js, React, Next.js, and other frameworks on macOS, Linux, and Windows.