Angular : Error: Uncaught (in promise) at webpackAsyncContext (eval at ./src/$$_lazy_route_resource

Question

I'm upgrading from Angular 4.0.0 to Angular 5.2.6

i'm facing some problem to get lazy module loading working.

with angular 4.0.0 , it works fine , but now , with 5.2.6 , i getting such an error when clicking my redirecting button :

core.js:1448 ERROR Error: Uncaught (in promise): TypeError: undefined is not a function
TypeError: undefined is not a function
    at Array.map (<anonymous>)
    at webpackAsyncContext (eval at ./src/$$_lazy_route_resource lazy recursive (main.bundle.js:27), <anonymous>:13:34)
    at SystemJsNgModuleLoader.loadAndCompile (core.js:6558)
    at SystemJsNgModuleLoader.load (core.js:6542)
    at RouterConfigLoader.loadModuleFactory (router.js:4543)
    at RouterConfigLoader.load (router.js:4523)
    at MergeMapSubscriber.eval [as project] (router.js:2015)
    at MergeMapSubscriber._tryNext (mergeMap.js:128)
    at MergeMapSubscriber._next (mergeMap.js:118)
    at MergeMapSubscriber.Subscriber.next (Subscriber.js:92)
    at Array.map (<anonymous>)
    at webpackAsyncContext (eval at ./src/$$_lazy_route_resource lazy recursive (main.bundle.js:27), <anonymous>:13:34)
    at SystemJsNgModuleLoader.loadAndCompile (core.js:6558)
    at SystemJsNgModuleLoader.load (core.js:6542)
    at RouterConfigLoader.loadModuleFactory (router.js:4543)
    at RouterConfigLoader.load (router.js:4523)
    at MergeMapSubscriber.eval [as project] (router.js:2015)
    at MergeMapSubscriber._tryNext (mergeMap.js:128)
    at MergeMapSubscriber._next (mergeMap.js:118)
    at MergeMapSubscriber.Subscriber.next (Subscriber.js:92)
    at resolvePromise (zone.js:809)
    at resolvePromise (zone.js:775)
    at eval (zone.js:858)
    at ZoneDelegate.invokeTask (zone.js:421)
    at Object.onInvokeTask (core.js:4740)
    at ZoneDelegate.invokeTask (zone.js:420)
    at Zone.runTask (zone.js:188)
    at drainMicroTaskQueue (zone.js:595)
    at ZoneTask.invokeTask [as invoke] (zone.js:500)
    at invokeTask (zone.js:1517)

my routing file looks like this :

const homeRoutes: Routes = [
  {
    path: 'home', component: HomeComponent,
    children: [
        ....
      {
        path: 'admin',
        loadChildren: 'app/home/admin/admin.module#AdminModule',
        canActivate: [AuthGuardAdmin]
      },
    ]
  },
];

@NgModule({
  imports: [
    CommonModule,
    RouterModule.forChild(homeRoutes)
  ],
  exports: [
    RouterModule
  ],
  declarations: []
})
export class HomeRoutingModule { }

suggestions ??

Answer 1

Do not import your lazy loaded module within your main app.module.ts. This will cause a circular dependency and throw the error you are receiving.