How to fix Angular 2 `Uncaught (in promise): TypeError: Cannot read property 'query' of null`?

Question

I\'ve been using the Heroes tutorial in the Angular 2 docs to experiment. However, I\'ve come to a point that I don\'t understand what\'s happening with this error:

Answer 1

I got this error with angular RC1 when I was injecting FormBuilder inside the constructor like this:

export class App {
  constructor(public formBuilder: FormBuilder) {}
}

But I didn't import it previously! Just add it solves the problem:

import { FormBuilder } from '@angular/common'