title: Error: Unexpected value 'undefined' imported by the module
body: <p>I'm getting this error after migrating to NgModule, the error doesn't help too much, any advice please?</p>
  
  <pre><code>Error: Error: Unexpected value 'undefined' imported by the module 'AppModule'
          at new BaseException (http://localhost:5555/node_modules/@angular/compiler/bundles/compiler.umd.js:5116:27)
          at eval (http://localhost:5555/node_modules/@angular/compiler/bundles/compiler.umd.js:13231:35)
          at Array.forEach (native)
          at CompileMetadataResolver.getNgModuleMetadata (http://localhost:5555/node_modules/@angular/compiler/bundles/compiler.umd.js:13215:48)
          at RuntimeCompiler._compileComponents (http://localhost:5555/node_modules/@angular/compiler/bundles/compiler.umd.js:15845:51)
          at RuntimeCompiler._compileModuleAndComponents (http://localhost:5555/node_modules/@angular/compiler/bundles/compiler.umd.js:15769:41)
          at RuntimeCompiler.compileModuleAsync (http://localhost:5555/node_modules/@angular/compiler/bundles/compiler.umd.js:15746:25)
          at PlatformRef_._bootstrapModuleWithZone (http://localhost:5555/node_modules/@angular/core/bundles/core.umd.js:9991:29)
          at PlatformRef_.bootstrapModule (http://localhost:5555/node_modules/@angular/core/bundles/core.umd.js:9984:25)
          at Object.eval (http://localhost:5555/app/main.js:8:53)
      Evaluating http://localhost:5555/app/main.js
      Error loading http://localhost:5555/app/main.js "Report this error at https://github.com/mgechev/angular2-seed/issues"(anonymous function) @ contracts:142ZoneDelegate.invoke @ zone.js?1472711930202:332Zone.run @ zone.js?1472711930202:225(anonymous function) @ zone.js?1472711930202:586ZoneDelegate.invokeTask @ zone.js?1472711930202:365Zone.runTask @ zone.js?1472711930202:265drainMicroTaskQueue @ zone.js?1472711930202:491ZoneTask.invoke @ zone.js?1472711930202:435
  </code></pre>
  
  <p>app.module.ts:</p>
  
  <pre><code>    import { NgModule } from '@angular/core';
      import { BrowserModule } from '@angular/platform-browser';
      import { APP_BASE_HREF } from '@angular/common';
      import { RouterModule } from '@angular/router';
      import { HttpModule } from '@angular/http';
      import { AppComponent } from './app.component';
      import { routes } from './app.routes';
  
      import { provide } from '@angular/core';
  
      //dgf ng2-translate
      import { TRANSLATE_PROVIDERS, TranslateLoader, TranslateStaticLoader, MissingTranslationHandler } from 'ng2-translate/ng2-translate';
      import { HTTP_PROVIDERS, Http } from '@angular/http';
      import { FormsModule,ReactiveFormsModule } from '@angular/forms';
      import { TranslationNotFoundHandler } from './shared/common/TranslationNotFoundHandler';
      //dgf ng2-translate END
  
      import {CalendarModule,DataTableModule,DialogModule,PanelModule} from 'primeng/primeng';
  
      import {TranslateModule} from 'ng2-translate/ng2-translate';
  
      import { AuthGuard,AppConfigService,AppConfig,DateHelper,ThemeComponent,ToolbarComponent, RemoveHostTagDirective } from './index';
      import { HomeComponent,MessagesExampleComponent,PrimeNgHomeComponent,CalendarComponent,Ng2BootstrapExamplesComponent,DatepickerDemoComponent,UserListComponent,UserEditComponent,ContractListComponent,AboutComponent } from './index';
  
  
  @NgModule({
    imports: [BrowserModule, HttpModule, RouterModule.forRoot(routes), /* AboutModule, HomeModule, SharedModule.forRoot()*/
            FormsModule,
            ReactiveFormsModule,
            //third-party
            ,TranslateModule.forRoot() //,
            //third-party PRIMENG
            ,CalendarModule,DataTableModule,DialogModule,PanelModule
    ],
    declarations: [
      AppComponent,ThemeComponent, ToolbarComponent, RemoveHostTagDirective,
      HomeComponent,MessagesExampleComponent,PrimeNgHomeComponent,CalendarComponent,Ng2BootstrapExamplesComponent,DatepickerDemoComponent,UserListComponent,UserEditComponent,ContractListComponent,AboutComponent
    ],
    providers: [{
        provide: APP_BASE_HREF,
        useValue: '&lt;%= APP_BASE %&gt;'
      },
      FormsModule,
      ReactiveFormsModule,
      provide(TranslateLoader, { //DGF ng2-translate
            useFactory: (http: Http) =&gt; new TranslateStaticLoader(http, 'assets/i18n', '.json'),
            deps: [Http]
        }),
      provide(MissingTranslationHandler, { useClass: TranslationNotFoundHandler }), //DGF ng2-translate
  
      AuthGuard,AppConfigService,AppConfig,
      DateHelper
    ],
    bootstrap: [AppComponent]
  })
  
  export class AppModule { }
  </code></pre>