Angular 6 Lazy Loading Issue

I am using below code for lazy loading

const routes: Routes = [
  { path: '', redirectTo: '/home', pathMatch: 'full' },
  { path: 'home', component: HomeComponent },
  { path: 'manager', loadChildren: './manager/manager.module#ManagerModule' },
  { path: '**', component: PageNotFoundComponent },
]

I am getting below error

ERROR Error: Uncaught (in promise): TypeError: undefined is not a function

If I run the project with ng serve --aot it works but if I run npm start it start throwing error

I found issue, issue what that when I create component from angular cli it was getting added to the app component and I was calling children component in routing. So it was creating loop and it was getting error. Now it is resolved