Фактически обнаружил, что я включил 'httpModule' вместо 'httpClient'.
я исправил его, заменив в своем коде
import { NgModule, ErrorHandler } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { IonicApp, IonicModule, IonicErrorHandler } from 'ionic-angular';
import { MyApp } from './app.component';
import { HttpModule } from '@angular/http';
import { HttpClient } from '@angular/common/http';
import { AboutPage } from '../pages/about/about';
import { ContactPage } from '../pages/contact/contact';
import { HomePage } from '../pages/home/home';
import { TabsPage } from '../pages/tabs/tabs';
import { SettingsPage } from '../pages/settings/settings';
import { StatusBar } from '@ionic-native/status-bar';
import { SplashScreen } from '@ionic-native/splash-screen';
import { WeatherProvider } from '../providers/weather/weather';
@NgModule({
declarations: [
MyApp,
AboutPage,
ContactPage,
HomePage,
TabsPage,
SettingsPage
],
imports: [
BrowserModule,
HttpClient,
HttpModule,
IonicModule.forRoot(MyApp),
],
bootstrap: [IonicApp],
entryComponents: [
MyApp,
AboutPage,
ContactPage,
HomePage,
TabsPage,
SettingsPage
],
providers: [
StatusBar,
SplashScreen,
{provide: ErrorHandler, useClass: IonicErrorHandler},
WeatherProvider
]
})
export class AppModule {}