Error map
NG0955 Angular: NG0955: The provided track expression resulted in duplicated keys for a given collection (@for)
Angular · layer 1, On your device
Centre: this error. First ring: errors it is linked with (7). 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 (7)
Angular: NG0100: ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was checked
A template value changed during the same change-detection cycle in which Angular already checked it (dev-mode only error).
Angular: NG8103: The *ngIf directive was used, but neither the NgIf directive nor the CommonModule was imported
A standalone component uses `*ngIf`, `*ngFor` or `ngClass` without importing the directive — or should migrate to the built-in `@…
Angular: Error: Cannot find control with name: 'email' (reactive forms)
A `formControlName` points at a control that does not exist in the bound `FormGroup`.
Angular: NG02200: Cannot find a differ supporting object '[object Object]' of type 'object'. NgFor only supports binding to Iterables such as Arrays
`*ngFor` (or `@for`) was given an object, `null` shape or a non-iterable instead of an array.
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.
Angular CLI: Schema validation failed with the following errors: Data path "" must NOT have additional properties(xyz)
`angular.json` (or an option you passed to a builder) contains a property the schema does not allow — a typo, an option removed i…
Angular CLI: Could not find the '@angular-devkit/build-angular:browser' builder's node package / Cannot find module '@angular-devkit/build-angular/package.json'
The build tooling package is missing from `node_modules` — dependencies were not installed or the lockfile/install is broken.
Two steps away (20)
Angular: NullInjectorError: No provider for X!
Angular’s dependency injection couldn’t find a provider for a service/token the component needs.
Angular: NG8002: Can't bind to 'ngModel' since it isn't a known property of 'input'
The template uses a property binding that no imported directive provides — for ngModel, FormsModule isn’t imported.
TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor
With strictPropertyInitialization on, a class property declared without ? or a default isn’t set in the constructor.
Angular: NG8001: 'app-item' is not a known element — verify that it is included in the component's imports
The template uses a tag Angular does not recognise as a component — it was never imported (standalone) or declared/exported (NgMo…
Angular: NG8004: No pipe found with name 'async' / 'date' / 'translate' — pipe not imported
The template uses a pipe Angular does not know — it is not imported into the component (standalone) or its module.
Angular: NG8113: NgIf is not used within the template of AppComponent — unused standalone import
A standalone component lists a directive, pipe or component in `imports` but never uses it in its template.
Angular: NG8003: No directive found with exportAs 'ngForm' (template reference variable)
A template reference such as `#f="ngForm"` points at a directive Angular cannot find on that element — the module that provides i…
Angular: NG01203: No value accessor for form control with name: 'x' (ControlValueAccessor missing)
A form directive (`formControlName`, `ngModel`) is on an element or component that Angular cannot read/write values from.
Angular: NG01050: formControlName must be used with a parent formGroup directive
`formControlName` is used outside any `[formGroup]` — the control has no form to belong to.
Angular: NG0301: Export of name 'x' not found! (template variable #x="exportAs")
A template variable asks for a directive by `exportAs` name, but no directive with that export is on the element at runtime.
Angular: NG02100: InvalidPipeArgument: '[object Object]' for pipe 'AsyncPipe'
The `async` pipe received a plain object or array instead of an Observable or Promise.
ChunkLoadError: Loading chunk 123 failed.
A lazily loaded JavaScript chunk couldn’t be downloaded — usually because a new deployment removed the old hashed files.
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: NG0203: inject() must be called from an injection context such as a constructor, a factory function, a field initializer or a function used with runInInjectionContext
`inject()` was called somewhere Angular is not constructing a class — for example inside a method, a callback or after an `await`.
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.
Angular SSR: NG0500: During hydration Angular expected <div> but found <span> (NG0501, NG0502)
The HTML rendered on the server does not match what the browser's Angular app tried to render, so hydration failed and the page w…
npm ERR! enoent ENOENT: no such file or directory, open '/path/package.json'
npm ran in a directory without a package.json.
Angular: NG0600: Writing to signals is not allowed in a computed or an effect by default
A `computed()` (or, by default, an `effect()`) tried to call `.set()` or `.update()` on a signal — that creates hidden update loo…
Angular: NG02100: InvalidPipeArgument: 'Unable to convert "x" into a date' for pipe 'DatePipe'
The `date` pipe was given a value it cannot turn into a Date — an invalid string, a non-ISO format, `null` handled wrongly or a s…
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