angular

Structural directive not available

Error: NG0901.*ngIf|ngFor|ngSwitch

Fixes

1.Import CommonModule in your feature module's imports array
2.For standalone components, add CommonModule to the component's imports
3.Check that BrowserModule is only imported in AppModule — use CommonModule elsewhere

templatedirectivescommonmodule

Related Errors

ExpressionChangedAfterItHasBeenCheckedError (NG0100)

NG0100.*Expression has changed after it was checked

•Move the value change to ngAfterViewInit with a ChangeDetectorRef.detectChanges() call
•Use setTimeout(() => { ... }) to defer the change to the next cycle

Circular dependency in DI (NG0200)

NG0200.*Circular dependency in DI detected

•Break the cycle by injecting one service lazily with `@Inject(forwardRef(() => ServiceName))`
•Extract shared logic into a third service that both services depend on

NullInjectorError — missing provider

NullInjectorError: No provider for (\w+)

•Add the service to the `providers` array of the module or component that needs it
•Use `@Injectable({ providedIn: 'root' })` on the service class for app-wide singleton