"Module" is not part of any NgModule or the module has not been imported into your module
<p>I have an application with some modules.</p>

<p>Here is my root module:</p>

<pre><code>// imports...

@NgModule({
    bootstrap: [ AppModule ],
    declarations: [
        AppComponent,
        ...APP_PIPES // Array with my pipes
    ],
    imports: [ // import Angular's modules
        BrowserModule,
        FormsModule,
        ReactiveFormsModule,
        HttpModule,
        RouterModule.forRoot(ROUTES),
        ...APP_MODULES, // Array with my modules
        ...THIRD_PARTY_MODULES // Array with libs modules
    ],
    providers: [ // expose our Services and Providers into Angular's dependency injection
        ENV_PROVIDERS,
        APP_PROVIDERS
    ]
})
export class AppModule {
 ...
}
</code></pre>

<p>And here's <strong>ONE</strong> of my <em>common</em> modules:</p>

<pre><code>import { CommonModule } from '@angular/common';
import { NgModule } from '@angular/core';

import { MenuComponent } from './menu.component';

@NgModule({
    declarations: [ MenuComponent ],
    exports: [ MenuComponent ],
    imports: [ CommonModule ],
    providers: [ ]
})

export class MenuModule {
  ...
}
</code></pre>

<p>I thought it's the correct way to do this, however I'm getting the following error:</p>

<blockquote>
  <p>AppModule is not part of any NgModule or the module has not been
  imported into your module</p>
</blockquote>

<p>I searched for AppModule in my whole application and I'm using only it in my <code>app.module.ts</code>.</p>

<p>Am I missing to import/export something? Any help would be great. Thanks.</p>