Angular 2 Stuck on Loading AppComponent content here - angularjs

Question

I have been following along to this tutorial on youtube to learn Angular 2. Just after the 33:00 mark, where I import the headerComponent into the app.module.ts, localhost begins perpetually displaying "Loading AppComponent content here". Meanwhile, in the video, the header and content load almost immediately. What am I doing wrong? Here is my code:
app.component.ts:
import { Component } from '#angular/core';
import { headerComponent } from './header/app.headerComponent';
#Component({
selector: 'my-app',
templateUrl: './main.html',
})
export class AppComponent {
}
app.headerComponent.ts:
import { Component } from '#angular/core';
#Component({
selector: 'header',
templateUrl: './header/header.html',
})
export class headerComponent {
}
app.module.ts:
import { NgModule } from '#angular/core';
import { BrowserModule } from '#angular/platform-browser';
import { AppComponent } from './app.component';
import { headerComponent } from './header/app.headerComponent';
#NgModule({
imports: [ BrowserModule ],
declarations: [ AppComponent, headerComponent ],
bootstrap: [ AppComponent ]
})
export class AppModule { }

Answer 1

Credit goes to TK Omble for finding out the issue. There was a build error because I was loading a header template from a folder called header within header folder. Now I changed the templateUrl: './header/header.html' to templateUrl: './header.html' and it works fine.