I am doing the angular2 tutorial at this address: https://angular.io/docs/ts/latest/tutorial/toh-pt3.html I have put the hero interface in a single
angular2
hero
probably you forgot to add "Export" in the class definition.
-->
export class Hero { id: number; name: string; }
Also, try with
export {Hero}
at the bottom of your hero.ts class, and finally, check capital letter file name and class name.