Unexpected value 'undefined' imported by the module 'AppModule'

Ionic Framework ionic-v3
1

Dear friends, completely new to ionic but wanting to learn as quick as possible, I need your kindest help.
Basically, developing an app with ionic 3.19 that displays the current weather and a weather forecast in two tabs (WeatherPage and ForecastPage).
And getting: Unexpected value ‘undefined’ imported by the module ‘AppModule’
My app.module.ts:

import { BrowserModule } from ‘@angular/platform-browser’;
import { ErrorHandler, NgModule } from ‘@angular/core’;
import { IonicApp, IonicErrorHandler, IonicModule } from ‘ionic-angular’;
import { SplashScreen } from ‘@ionic-native/splash-screen’;
import { StatusBar } from ‘@ionic-native/status-bar’;

import { MyApp } from ‘./app.component’;

import { WeatherApiPage } from ‘…/pages/weather-api/weather-api’;
import { ForecastPage } from ‘…/pages/forecast/forecast’;
import { WeatherPage } from ‘…/pages/weather/weather’;
import { AppConstants } from ‘…/providers/app-constants/app-constants’;
import { WeatherApi } from ‘…/providers/weather-api/weather-api’;
import { ChartModule } from ‘highcharts’;

@NgModule({
declarations: [
MyApp,
WeatherApiPage,
ForecastPage,
WeatherPage
],
imports: [
ChartModule,
BrowserModule,
IonicModule.forRoot(MyApp)
],
bootstrap: [IonicApp],
entryComponents: [
MyApp,
WeatherApiPage,
ForecastPage,
WeatherPage
],
providers: [
StatusBar,
SplashScreen,
{provide: ErrorHandler, useClass: IonicErrorHandler},
AppConstants,
WeatherApi
]
})
export class AppModule {}

Any ideas to fix it? Thank you very much!