Error map
DEP0040 DeprecationWarning: The `punycode` module is deprecated (DEP0040)
Node.js · layer 4, Application & API
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)
java.lang.ClassNotFoundException / NoClassDefFoundError
The JVM couldn’t find a class on the classpath at runtime.
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.
npm WARN EBADENGINE Unsupported engine / The engine "node" is incompatible with this module
A package requires a different Node.js version than the one you’re running.
Gradle: Could not resolve all files for configuration / Could not resolve dependency
Gradle couldn’t download a dependency — wrong coordinates/version, missing repository, offline mode, or network/proxy issues.
Warning: findDOMNode is deprecated and will be removed in the next major release.
A component (often an old library like react-transition-group v1, react-draggable) uses findDOMNode, which StrictMode flags and R…
Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './x' is not defined by "exports"
You imported a deep path inside a package that its package.json "exports" field doesn’t expose.
Error: Unhandled 'error' event (events.js / node:events)
An EventEmitter (stream, socket, child process, server) emitted 'error' and nothing listened for it, so Node crashed.
DeprecationWarning: Buffer() is deprecated due to security and usability issues (DEP0005)
Code (yours or a dependency) uses the deprecated new Buffer() constructor.
WRONGTYPE Operation against a key holding the wrong kind of value
A Redis command was used on a key of a different type (e.g. HGET on a string key).
Error: Node Sass does not yet support your current environment
node-sass (deprecated) has no binary for your Node version/OS.
Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated
PHP 8.1+ warns when null is passed to a built-in function that expects a string/int.
Warning: componentWillMount has been renamed, and is not recommended for use.
A class component uses legacy lifecycle methods (componentWillMount/WillReceiveProps/WillUpdate).
Two steps away (35)
PHP Fatal error: Uncaught Error: Class "X" not found
PHP couldn’t load the class — autoloading failed, the namespace is wrong, or the dependency isn’t installed.
ModuleNotFoundError: No module named 'x'
Python can’t find the module you import — it isn’t installed in the interpreter/virtualenv that’s running, or the import path is…
java.lang.NullPointerException
Code called a method or accessed a field on a reference that is `null`.
npm ERR! code ERESOLVE — unable to resolve dependency tree
npm 7+ found conflicting peer dependency requirements and refuses to install a broken tree.
Error: ENOENT: no such file or directory
A file or directory the program tried to open doesn’t exist at that path.
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…).
Duplicate class X found in modules A and B
Two dependencies ship the same class — typically old Android Support libraries mixed with AndroidX, or Kotlin stdlib-jdk7/jdk8 ve…
Runtime.ImportModuleError: Unable to import module 'lambda_function': No module named 'x'
Lambda couldn’t load your handler file or one of its dependencies — the package is missing from the deployment zip/layer or the h…
Unmet dependencies / E: Unable to correct problems, you have held broken packages
apt can’t find a set of package versions that satisfies all dependencies — usually mixed repositories or a package from another r…
Android: INSTALL_FAILED_UPDATE_INCOMPATIBLE
An app with the same package name but a different signing key is already installed on the device.
Manifest merger failed: android:exported needs to be explicitly specified
Targeting Android 12 (API 31)+ requires `android:exported` on every activity, service or receiver that has an intent-filter.
Gradle: Unsupported class file major version / Android Gradle plugin requires Java 17 to run
The JDK running Gradle doesn’t match what the Gradle version or Android Gradle Plugin (AGP) supports.
Authentication plugin 'caching_sha2_password' cannot be loaded
An old MySQL client/driver can’t use MySQL 8’s default authentication plugin.
npm WARN config global `--global`, `--local` are deprecated. Use `--location=global` instead.
A deprecation warning printed by npm 8.11–8.12 for the --global flag.
Warning: ReactDOM.render is no longer supported in React 18. Use createRoot instead.
The app uses the legacy root API, so React 18 features (concurrent rendering, automatic batching) are disabled.
Error [ERR_REQUIRE_ESM]: require() of ES Module not supported
CommonJS code used `require()` on a package that is ES-module-only (node-fetch 3, chalk 5, nanoid 4, got 12…).
SyntaxError: Cannot use import statement outside a module
An `import` statement ran in a context treated as CommonJS (Node without "type": "module", a browser script without type="module"…
TypeError [ERR_IMPORT_ATTRIBUTE_MISSING]: Module needs an import attribute of "type: json"
An ES module imported a .json file without the required import attribute.
Error: listen EADDRINUSE: address already in use :::3000
Another process is already listening on that port.
Error: listen EACCES: permission denied 0.0.0.0:80
Node isn’t allowed to bind that port — ports below 1024 need root on Linux/macOS, and some Windows ports are reserved.
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.
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
An Express/Node handler tried to send a second response (or set headers) after one was already sent.
Express: req.body is undefined / {} (body parser missing)
Express didn’t parse the request body because no body-parsing middleware matched the request’s Content-Type.
npm WARN deprecated package@1.2.3: This package is no longer supported.
A dependency (often a transitive one) is deprecated by its author.
ReplyError: NOAUTH Authentication required.
The Redis server requires a password (or ACL user) but the client didn’t authenticate.
WordPress: Error establishing a Redis connection (object cache)
The persistent object cache drop-in (object-cache.php) can’t connect to Redis, so the whole site fails.
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.
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: 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.
Deprecated: Creation of dynamic property Foo::$bar is deprecated
PHP 8.2+ deprecates creating properties that aren’t declared in the class.
Fatal error: Uncaught TypeError: Unsupported operand types: string + int
An arithmetic or array operator was used with incompatible types (PHP 8 is stricter than PHP 7).
Deprecated: Implicit conversion from float 2.5 to int loses precision
PHP 8.1+ warns when a float with a fractional part is silently converted to int (array keys, % operator, int parameters).
[vite] hmr invalidate … Could not Fast Refresh. Export is incompatible.
Fast Refresh fell back to a full reload because the file exports non-components alongside components.
Warning: Function components cannot be given refs. Attempts to access this ref will fail. Did you mean to use React.forwardRef()?
A ref was passed to a function component that doesn’t forward it.
Warning: Support for defaultProps will be removed from function components in a future major release.
A function component (often inside a library) uses Component.defaultProps.
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