ionic2 CloudModule.forRoot() error angular.element is not function - ionic2

Question

i try to setup ionic Cloud in my app, but i have this error : Uncaught TypeError: angular.element is not a function(…) for this line :
CloudModule.forRoot(cloudSettings)
my code : for app.module.ts
import { NgModule, ErrorHandler } from '#angular/core';
import { IonicApp, IonicModule, IonicErrorHandler } from 'ionic-angular';
import { CloudSettings, CloudModule } from '#ionic/cloud-angular';
import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
import {DetailsPage} from '../pages/details/details';
import {OtherPage} from '../pages/other-page/other-page';
import { Page1 } from '../pages/page1/page1';
import { Page2 } from '../pages/page2/page2';
var cloudSettings: CloudSettings = {
'core': {
'app_id': 'xxxxx'
}
};
console.log(cloudSettings);
#NgModule({
declarations: [
MyApp,
HomePage
],
imports: [
IonicModule.forRoot(MyApp),
CloudModule.forRoot(cloudSettings)
],
bootstrap: [IonicApp],
entryComponents: [
MyApp,
HomePage
],
providers: [{provide: ErrorHandler , useClass:IonicErrorHandler}]
})
export class AppModule {}
thank's you,