Error map
Http failure response for (unknown url): 0 Unknown Error Angular: HttpErrorResponse — Http failure response for (unknown url): 0 Unknown Error (status 0)
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: Failed to fetch / NetworkError when attempting to fetch resource
The browser couldn’t complete the request at the network level — CORS, DNS, offline, blocked mixed content, or the server refused…
CORS Error: No 'Access-Control-Allow-Origin' header is present
The browser blocked a cross-origin request because the server’s response didn’t include the CORS headers allowing your site’s ori…
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: Http failure response for http://…/api/x: 404 Not Found (HttpErrorResponse)
The API answered 404 — the URL is wrong (base URL, path or id), or the proxy/rewrite does not forward the request.
Angular: Http failure during parsing for http://…: SyntaxError: Unexpected token '<' (response is not JSON)
The request succeeded (status 200) but the body could not be parsed as the expected type — usually HTML or plain text instead of…
Angular CLI: [HPM] Error occurred while proxying request localhost:4200 to http://localhost:3000 [ECONNREFUSED]
The `ng serve` dev proxy cannot forward your API call — it was not enabled, the path does not match, or the target server is down.
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 (19)
Error: connect ECONNREFUSED 127.0.0.1:5432
Nothing is listening at that host:port — the target service is down or you’re connecting to the wrong address.
SyntaxError: Unexpected token < in JSON at position 0
`JSON.parse()` / `response.json()` received something that isn’t JSON — very often an HTML error page.
SSL: CERTIFICATE_VERIFY_FAILED / unable to get local issuer certificate
The client couldn’t verify the server’s TLS certificate chain, so it refused the HTTPS connection.
AWS S3: AccessDenied (403) when calling GetObject / PutObject
An IAM policy, bucket policy, ACL/ownership setting, Block Public Access or KMS key policy denied the S3 request.
HTTP 401 Unauthorized
The request has no valid authentication credentials — you need to log in or send a valid token.
HTTP 403 Forbidden
The server understood the request but refuses to authorize it — you (or the server process) are not allowed to access this resour…
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.
HTTP 404 Not Found
The server can’t find anything at the requested URL.
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.
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).
API Error: Malformed JSON in request body (entity.parse.failed / JSON parse error)
The server couldn’t parse the request body as JSON, so it rejected the request before looking at any field.
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.
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 CLI: Port 4200 is already in use. Use '--port' to specify a different port
Another process is already listening on the dev-server port, often an earlier `ng serve` that was not stopped.
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…
Map another error
Popular: 4035004000xC000007BTypeErrorCritical error404NullPointerException