Cannot read property 'outlets' of null
<p>I have next problem : <code>Cannot read property 'outlets' of null</code>. My project works, but after some time it stopped working, but i didn't change my code. Help me please.<br>
<strong>Update</strong><br>
My component with router-outlet:  </p>

<pre class="lang-ts prettyprint-override"><code>import { Component } from '@angular/core';

@Component({
  selector: 'app',
  template: '
    &lt;nav-menu&gt;&lt;/nav-menu&gt;
    &lt;router-outlet&gt;&lt;/router-outlet&gt;
    &lt;footer-component&gt;&lt;/footer-component&gt;

',
})
export class AppComponent  {}
</code></pre>

<p>app.module:  </p>

<pre class="lang-ts prettyprint-override"><code>import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { RouterModule } from '@angular/router';
import { LocationStrategy, PathLocationStrategy, APP_BASE_HREF } from       '@angular/common';
import { HttpModule } from '@angular/http';
import {FormsModule,ReactiveFormsModule} from '@angular/forms';
//+components
@NgModule({
    imports:
    [
        BrowserModule,
        HttpModule,
        FormsModule,
        ReactiveFormsModule,
        RouterModule.forRoot([
            { path: '', component: HomeComponent },
            { path: 'home', component: HomeComponent },
            { path: 'blog', component: BlogComponent },
            { path: '2016/:link', component: BlogArticleFullComponent },
            {
                path: 'admin', component: AdminComponent, 
                children: [
                    { path: 'new', component: NewArticleComponent },
                    { path: 'new-writer', component: NewWriterComponent },
                    { path: 'new-tag', component: NewTagComponent }
                ] },
            { path: '**', redirectTo: '', pathMatch: 'full'}
        ])
    ],
    declarations:
    [//components
    ],
    bootstrap:
    [
        AppComponent
    ],
    providers:
    [
        { provide: APP_BASE_HREF, useValue: '/' },
        { provide: LocationStrategy, useClass: PathLocationStrategy }
    ]
})
export class AppModule { }
</code></pre>

<p>P.S. There is ' quote against ` because stackoverflow ``-is code.</p>