[angular] No provider for Router?

If you created a separate module (eg. AppRoutingModule) to contain your routing commands you can get this same error:

Error: StaticInjectorError(AppModule)[RouterLinkWithHref -> Router]: 
StaticInjectorError(Platform: core)[RouterLinkWithHref -> Router]: 
NullInjectorError: No provider for Router!

You may have forgotten to import it to the main AppModule as shown here:

@NgModule({
  imports:      [ BrowserModule, FormsModule, RouterModule, AppRoutingModule ],
  declarations: [ AppComponent, Page1Component, Page2Component ],
  bootstrap:    [ AppComponent ]
})
export class AppModule { }