I created a simple app with routing. Links "http:// localhost:4200" and "http:// localhost:4200/mail" work well,
but when I try to open a link "http:// localhost:4200/mail/inbox" I get an error: "Cannot find primary outlet to load 'InboxComponent'".
What causes the error and how can I fix it?
Here are my *.ts files:
app.module.ts :
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { RouterModule } from '@angular/router';
import { AppComponent } from './app.component';
import { MailListComponent } from './components/mail-list/mail-list.component';
import { FoldersComponent } from './components/folders/folders.component';
import { InboxComponent } from './components/inbox/inbox.component';
const routes = [
  { path: '',
    component: MailListComponent
   },
  { path: 'mail', component: MailListComponent,
      children: [
        {path: 'inbox', component: InboxComponent}
      ]
  }
];
@NgModule({
  declarations: [
    AppComponent,
    MailListComponent,
    FoldersComponent,
    InboxComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    RouterModule.forRoot(routes)
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }
app.component.ts :
import { Component } from '@angular/core';
@Component({
  selector: 'app-root',
  template: `
    <app-folders></app-folders>
    <router-outlet></router-outlet>
  `,
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'app works!';
}
folders.component.ts :
import { Component } from '@angular/core';
@Component({
  selector: 'app-folders',
  template: `
    <aside class="folders">
      <ul>
        <li><a routerLink="mail/inbox">Inbox</a></li>
      </ul>
    </aside>
  `,
  styleUrls: ['./folders.component.css']
})
export class FoldersComponent {
  folders: any[];
  constructor() { }
}
mail-list.component.ts :
import { Component } from '@angular/core';
@Component({
  selector: 'app-mail-list',
  template: `
    <p>
      Mail list works!
    </p>
  `,
  styleUrls: ['./mail-list.component.css']
})
export class MailListComponent {
  constructor() { }
}
inbox.component.ts :
import { Component, OnInit } from '@angular/core';
@Component({
  selector: 'app-inbox',
  template: `
    <p>
      inbox works!
    </p>
  `,
  styleUrls: ['./inbox.component.css']
})
export class InboxComponent implements OnInit {
  constructor() { }
  ngOnInit() {
  }
}
 
     
    