Error map
Page is missing generateStaticParams() (output: export) Next.js: Page "/blog/[slug]" is missing "generateStaticParams()" so it cannot be used with "output: export" config
Next.js · layer 1, On your device
Centre: this error. First ring: errors it is linked with (12). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (12)
Error occurred prerendering page "/x". Read more: https://nextjs.org/docs/messages/prerender-error
A page threw an error while Next.js was rendering it at build time.
Next.js: Module not found: Can't resolve '@/components/Button' / 'lodash' in '/app/src'
Webpack/Turbopack couldn't resolve an import — wrong path/alias, missing dependency or case mismatch.
Vue: [Vue warn]: Component is missing template or render function.
A component object has neither `template` nor `render`, or an SFC import resolved wrongly.
Next.js: useSearchParams() should be wrapped in a suspense boundary at page "/". Read more: https://nextjs.org/docs/messages/missing-suspense-with-csr-bailout
A Client Component using `useSearchParams` is statically rendered, so the build needs a Suspense boundary for the client-only par…
Next.js: Failed to compile. ./src/app/page.tsx 12:7 Error: 'x' is assigned a value but never used. @typescript-eslint/no-unused-vars
`next build` runs ESLint and fails the build on lint errors.
Next.js: ⨯ Failed to download `Inter` from Google Fonts. Using fallback font instead / FetchError: request to https://fonts.googleapis.com failed
`next/font/google` couldn't download the font at build/dev time (offline, firewall or proxy).
Vue: [Vue warn]: Component provided template option but runtime compilation is not supported in this build of Vue. Configure your bundler to alias "vue" to "vue/dist/vue.esm-bundler.js"
A component uses a string `template` but the runtime-only Vue build has no compiler.
Next.js: Failed to compile. ./src/app/page.tsx:15:9 Type error: Type 'string | undefined' is not assignable to type 'string'
TypeScript type checking failed during `next build`, which blocks the deployment.
Next.js: FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory (during next build)
Node ran out of memory while building a large Next.js app (or on a small CI/Vercel runner).
Next.js: TypeError: Failed to parse URL from /api/posts (fetch in a Server Component)
`fetch('/api/x')` with a relative URL works in browsers but not on the server, which has no base URL.
Next.js: Error occurred prerendering page "/blog" TypeError: fetch failed { cause: Error: connect ECONNREFUSED 127.0.0.1:3000 }
During `next build` a page tried to fetch data from a server (often your own app or an API) that isn't running yet.
Next.js: Error: You cannot use different slug names for the same dynamic path ('id' !== 'slug')
Sibling dynamic folders at the same level use different parameter names.
Two steps away (36)
Error: Hydration failed because the initial UI does not match what was rendered on the server
The HTML rendered on the server differs from the first client render, so React (Next.js/Remix) can’t attach to it.
Module not found: Can't resolve 'fs' (Next.js / webpack 5)
A Node.js built-in (fs, path, crypto, net) is imported into code that runs in the browser bundle.
You're importing a component that needs useState. It only works in a Client Component but none of its parents are marked with "use client"
In the Next.js App Router, a component using hooks or browser APIs is rendered as a Server Component.
TypeError: x is not a function
You called something as a function, but its value is not a function (it’s undefined, a string, an object…).
TypeError: x is not a constructor
new was used with something that isn’t a class/constructor — usually a wrong import.
ReferenceError: Cannot access 'x' before initialization
A let/const/class was used before its declaration line ran (temporal dead zone) — often a circular import.
npm ERR! code ELIFECYCLE / Command failed with exit code 1
An npm script (build, start, test, postinstall) exited with an error. ELIFECYCLE is only the wrapper — the real error is printed…
gyp ERR! build error / node-gyp rebuild failed
A dependency with native C/C++ code couldn’t compile — missing build tools, Python, or an unsupported Node version.
Error: error:0308010C:digital envelope routines::unsupported
An old build tool (webpack 4, old react-scripts) uses a hash algorithm that OpenSSL 3 in Node 17+ disables.
Error: A component suspended while responding to synchronous input.
A component suspended (lazy load or data fetch) during an update that wasn’t wrapped in a transition, and there is no Suspense bo…
Error: Dynamic server usage: Route /x couldn't be rendered statically because it used `cookies`
Next.js tried to statically render a route that reads request-specific data (cookies, headers, searchParams).
Next.js 15: Error: Route "/blog/[slug]" used `params.slug`. `params` should be awaited before using its properties
In Next.js 15 `params` and `searchParams` are Promises; reading properties synchronously triggers this error/warning.
React Hook useEffect has a missing dependency (react-hooks/exhaustive-deps)
ESLint warns that the effect reads a value that isn’t in its dependency array, so it may use a stale value.
Error: @prisma/client did not initialize yet. Please run "prisma generate"
The generated Prisma Client is missing or out of date.
Error: Node Sass does not yet support your current environment
node-sass (deprecated) has no binary for your Node version/OS.
npm ERR! code ETIMEDOUT — network request to https://registry.npmjs.org/x failed, reason: connect ETIMEDOUT
npm couldn’t reach the registry in time — network, proxy or firewall issue.
Next.js: Error: Could not find a production build in the '.next' directory. Try building your app with 'next build' before starting the production server
`next start` was run without a prior successful `next build` (or the `.next` folder is missing).
Vue: You are running the esm-bundler build of Vue — configure your bundler to explicitly replace feature flag globals (__VUE_OPTIONS_API__)
A bundler build of Vue 3 lacks the feature-flag defines (`__VUE_OPTIONS_API__`, `__VUE_PROD_DEVTOOLS__`, `__VUE_PROD_HYDRATION_MI…
'react-scripts' is not recognized as an internal or external command / react-scripts: command not found
node_modules is missing or broken, so the react-scripts binary isn’t available.
Module parse failed: Unexpected token. You may need an appropriate loader to handle this file type
Webpack found syntax it can’t parse because no loader is configured for that file (JSX, TypeScript, CSS, or modern syntax in node…
Vue: [Vue warn]: Failed to resolve component: x
The template uses a component tag that isn’t registered or imported where it’s used.
TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts"
Node tried to run a TypeScript file as ESM without a TypeScript loader.
TS2307: Cannot find module 'x' or its corresponding type declarations.
TypeScript can’t resolve the import — the package isn’t installed, the path alias isn’t configured, or there are no types.
TS7016: Could not find a declaration file for module 'x'. 'x.js' implicitly has an 'any' type.
The JavaScript package has no TypeScript types bundled and no @types package installed.
FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory
The V8 heap hit its limit — a large build (webpack, tsc, Next.js) needs more memory, or the app leaks.
RangeError: Invalid string length
A string grew beyond the engine’s maximum length — usually runaway concatenation or huge JSON.stringify output.
MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 listeners added
More than 10 listeners were added to one event — often a leak where listeners are added repeatedly.
Warning: validateDOMNesting(...): <div> cannot appear as a descendant of <p>.
The JSX produces invalid HTML nesting, which also causes hydration mismatches in SSR.
Warning: useLayoutEffect does nothing on the server
A component using useLayoutEffect was server-rendered, where layout effects can’t run.
Warning: Prop `className` did not match. Server: "x" Client: "y"
A prop rendered on the server differs from the client — usually CSS-in-JS class names or random IDs.
Next.js: Warning: validateDOMNesting(...): <div> cannot appear as a descendant of <p> / In HTML, <p> cannot be a descendant of <p>. This will cause a hydration error
The rendered HTML has an invalid element nesting, so the browser "fixes" it and React's hydration no longer matches.
Next.js: ReferenceError: window is not defined (server-side rendering)
Code touching the browser's `window` ran on the server during SSR/build, where it doesn't exist.
Next.js: ReferenceError: document is not defined
Code used the DOM (`document`) while rendering on the server.
TypeError: Missing parameter name at 1 (path-to-regexp)
An Express 5 (path-to-regexp v8) route uses old wildcard syntax like '*' or '/:id?'.
No routes matched location "/x"
React Router found no route definition for the current URL.
Error: NextRouter was not mounted.
next/router’s useRouter was used inside the App Router (app/ directory), which uses next/navigation instead.
Map another error
Popular: 500403400ORA-009331064Critical errorFileNotFoundException assemblyTypeError