问题 I am trying to get a json file from HttpClient , but I get a error when I add .subscribe imports: import { Injectable } from '@angular/core'; import { HttpClient, HttpHeaders, HttpClientModule } from '@angular/common/http'; import { HttpModule, Request, Response, Headers, Http } from '@angular/http'; import { Observable } from 'rxjs'; My code: When I add .subscribe (yellow marked in image) I got the following error. What does it mean? Object { _body: error, status: 0, ok: false, statusText: "