import {NgModule} from '@angular/core';
import {Routes, RouterModule} from '@angular/router';
import {ComponentModuleOneProxyComponent} from './component-module-one-proxy/component-module-one-proxy.component';
import { ModuleOneModule } from './module-one/module-one.module';

const routes: Routes = [
  {
    path: '',
    outlet: 'module-one-outlet',
    component: ComponentModuleOneProxyComponent,
    children: [
      {
        path: '',
        loadChildren: () => ModuleOneModule
      }
    ],
  },
  {
    path: 'module-two',
    loadChildren: 'app/module-two/module-two.module#ModuleTwoModule'
  },
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule {
}

Error: Uncaught (in promise): TypeError: Cannot read property 'routes' of undefined