JAVASCRIPT

is an Angular component, then verify that it is part of this module.

@NgModule({
   imports: [],
   exports: [MyComponentComponent],
   declarations: [MyComponentComponent],
   providers: [],
})

export class MyComponentModule {
}

is an Angular component, then verify that it is part of this module.

import { MyComponentModule } from 'your/file/path';

@NgModule({
   imports: [MyComponentModule]
   declarations: [AppComponent],
   providers: [],
   bootstrap: [AppComponent]
})

export class AppModule {}