Error map
ChunkLoadError ChunkLoadError: Loading chunk 123 failed.
JavaScript · 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)
Could not load file or assembly 'X, Version=…' or one of its dependencies
The runtime couldn’t find or load a referenced DLL — missing from the output, wrong version, or wrong platform (x86/x64).
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…
Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/html"
A or dynamic import got HTML back instead of JavaScript.
SyntaxError: Unexpected token '<' (HTML served instead of JavaScript)
The browser loaded a .js file but received HTML (an error page or the SPA index.html).
DOMException: Failed to execute 'querySelector' on 'Document': 'x' is not a valid selector
The CSS selector string is invalid — often an ID starting with a digit or containing special characters.
PHP still runs old code after deploy (OPcache not reset)
OPcache keeps serving cached bytecode, so changes uploaded to the server don’t take effect.
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.
The framework 'Microsoft.NETCore.App', version '8.0.0' (x64) was not found. You must install or update .NET to run this application
The machine doesn’t have the .NET runtime version the app was built for (framework-dependent deployment).
Azure App Service: ":( Application Error" / container didn’t respond to HTTP pings
App Service started your app but it crashed or never listened on the expected port.
Refused to execute script from 'x' because its MIME type ('text/html') is not executable
The browser fetched a script but the server labelled it text/html (usually an error page), so it refused to run it.
DevTools: Failed to load source map — Could not load content for https://…/app.js.map: HTTP error: status code 404
DevTools could not download the `.map` file that a script or stylesheet points to, so you see minified code instead of your sourc…
Angular build: Error: bundle initial exceeded maximum budget. Budget 1.00 MB was not met by 120.00 kB with a total of 1.12 MB
The production build is larger than the size limits (budgets) in angular.json, and the build is configured to fail.
Two steps away (30)
java.lang.ClassNotFoundException / NoClassDefFoundError
The JVM couldn’t find a class on the classpath at runtime.
HTTP Error 500.30 - ASP.NET Core app failed to start
IIS/Azure’s ASP.NET Core Module launched your app but it crashed during startup.
error NETSDK1045: The current .NET SDK does not support targeting .NET 8.0. Either target .NET 7.0 or lower, or use a version of the .NET SDK that supports .NET 8.0
The installed .NET SDK is older than the project’s TargetFramework.
COPY failed: file not found in build context / "/app/x": not found
The Dockerfile COPY refers to a path outside the build context, excluded by .dockerignore, or relative to the wrong directory.
Error: Could not find or load main class org.gradle.wrapper.GradleWrapperMain
The Gradle wrapper JAR (gradle/wrapper/gradle-wrapper.jar) is missing or corrupt.
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.
Console: Refused to apply style from 'https://…/style.css' because its MIME type ('text/html') is not a supported stylesheet MIME type
The stylesheet URL returned something that is not CSS — usually a 404/HTML error page — and `X-Content-Type-Options: nosniff` mak…
Console: Failed to register a ServiceWorker: A bad HTTP response code (404) was received when fetching the script
The browser could not fetch, parse or install the service worker script, or the page is not allowed to register one (HTTPS and sc…
Console: Failed to find a valid digest in the 'integrity' attribute for resource … with computed SHA-256 integrity
A `` or `` with an `integrity` hash was blocked because the downloaded file does not match that hash.
SyntaxError: Unexpected token < in JSON at position 0
`JSON.parse()` / `response.json()` received something that isn’t JSON — very often an HTML error page.
SyntaxError: missing ) after argument list
A function call’s parentheses are unbalanced — often an unescaped quote or a missing comma/plus.
SyntaxError: Identifier 'x' has already been declared
The same let/const/class name was declared twice in the same scope.
TypeError: Cannot read properties of null (reading 'addEventListener')
document.querySelector/getElementById returned null, so the element doesn’t exist when the script runs.
ResizeObserver loop completed with undelivered notifications.
A ResizeObserver callback changed layout in a way that triggered another resize in the same frame.
AbortError: The user aborted a request. / signal is aborted without reason
A fetch was cancelled through an AbortController (or the browser cancelled it).
FastCGI sent in stderr: "Primary script unknown"
Nginx passed a script path to PHP-FPM that PHP-FPM couldn’t find — usually a wrong SCRIPT_FILENAME or root.
Error: Cannot find module 'x' (MODULE_NOT_FOUND)
Node can’t resolve the module path — the package isn’t installed, or a relative path/extension is wrong.
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.
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.
java.lang.UnsupportedClassVersionError: class file version 61.0, this version of the Java Runtime only recognizes up to 55.0
Code compiled for a newer Java version is running on an older JVM.
PlatformNotSupportedException: System.Drawing.Common is not supported on this platform
Since .NET 6, System.Drawing.Common only works on Windows; on Linux/macOS (including Docker) it throws.
Kubernetes: CrashLoopBackOff
The container starts, crashes (or exits), and Kubernetes keeps restarting it with increasing back-off delays.
HTTP 502 Bad Gateway
A proxy or gateway (Nginx, load balancer, CDN) got an invalid response — or no response — from the upstream server behind it.
Azure Functions: No job functions found. Try making your job classes and methods public / Error indexing method
The Functions host started but couldn’t discover or index any functions — wrong project structure, extension/binding problems or…
HTTP 404 Not Found
The server can’t find anything at the requested URL.
Chrome DevTools: net::ERR_FAILED — a request failed with no specific reason (CORS, extension, mixed content or network)
ERR_FAILED is Chrome’s catch-all for a failed request. In DevTools it very often hides a CORS rejection, an extension, or a block…
Chrome: Aw, Snap! Something went wrong while displaying this webpage. Error code: STATUS_ACCESS_VIOLATION / SIGILL / Out of Memory
A Chrome tab crashed — out of memory, a faulty extension, a graphics/driver issue or a very heavy page.
Angular: NG0200: Circular dependency in DI detected for X
Two or more services inject each other (directly or through a chain), so Angular cannot create any of them first.
Angular: NG0201: No provider for X found in NodeInjector
A component or directive asked for a service no injector in its tree provides.
Angular: NG0300: Multiple components match node with tagname app-x: A and B
Two components in scope share the same selector, so Angular cannot decide which one renders for that tag.
Map another error
Popular: 4035004000xC000007BTypeErrorCritical error404NullPointerException