Why is the component in this simple plunk
@Component({ selector: \'my-app\', template: `I\'m {{message}} `, }) export class App {
It throw an error because your code get updated when ngAfterViewInit() is called. Mean your initial value got changed when ngAfterViewInit take place, If you call that in ngAfterContentInit() then it will not throw an error.
ngAfterContentInit() { this.updateMessage(); }