模块'AppModule'导入的异常值'undefined'js 6

Question

我想在Angular页面中使用Owl Carousel滑块。我已经安装了Owl Carousel，并导入了所有需要的代码。但是，运行文件时出现此错误：

  

模块“ AppModule” Angular js 6导入的意外值“未定义”

有人能为我找到错误吗？

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { AboutComponent } from './about/about.component';
import { HeaderComponent } from './header/header.component';
import { NavbarComponent } from './navbar/navbar.component';
import { FooterComponent } from './footer/footer.component';
import { AppRoutingModule } from './app-routing.module';
import {OwlCarousel} from 'angular-owl-carousel2';
import { SlickModule } from 'ngx-slick';

@NgModule({
  declarations: [
    AppComponent,
    HomeComponent,
    AboutComponent,
    HeaderComponent,
    NavbarComponent,
    FooterComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
      OwlCarousel,
      SlickModule.forRoot()
      //RouterModule.forRoot(appRoutes)
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }