Error map
You provided 'undefined' where a stream was expected RxJS: TypeError: You provided 'undefined' where a stream was expected. You can provide an Observable, Promise, ReadableStream, Array, AsyncIterable, or Iterable.
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)
TypeError: Cannot read properties of undefined (reading 'length')
Code checked .length on something that is undefined — typically an array or string that hasn’t loaded.
Angular: NullInjectorError: No provider for HttpClient! — provideHttpClient() missing
A service or component injects `HttpClient`, but HTTP support was never added to the app's providers.
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: NG02100: InvalidPipeArgument: '[object Object]' for pipe 'AsyncPipe'
The `async` pipe received a plain object or array instead of an Observable or Promise.
RxJS: EmptyError: no elements in sequence (firstValueFrom / lastValueFrom on an empty Observable)
`firstValueFrom`, `lastValueFrom`, `first()` or `last()` waited for a value but the Observable completed without emitting.
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…
Two steps away (20)
TypeError: Cannot read properties of undefined (reading 'x')
You tried to access a property on a value that is `undefined` (or `null`) — usually data that hasn’t loaded yet or a wrong proper…
java.lang.ArrayIndexOutOfBoundsException: Index 5 out of bounds for length 5
Code accessed an array index outside 0 … length-1.
TypeError: Cannot set properties of undefined (setting 'x')
Code assigned a property on a value that is undefined (or null).
Angular: NullInjectorError: No provider for X!
Angular’s dependency injection couldn’t find a provider for a service/token the component needs.
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: 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: 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.
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: 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: 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…
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.
Node.js: [UnhandledPromiseRejection] — This error originated either by throwing inside of an async function without a catch block
A promise rejected and nothing handled it; since Node 15 this crashes the process.
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.
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: 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…
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: 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: NG0912: Component ID generation collision detected. Components 'A' and 'B' with selector 'app-x' use the same ID
Angular generated the same internal id for two different components — usually two components with the same selector, template and…
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