在IE浏览器中，未捕获（承诺）：错误：加载块模块名模块失败

Question

我在angular 7中使用了延迟加载概念。我创建了带有sidemenu的项目。在侧边菜单中路由页面时，出现“未捕获（承诺）：错误：加载块modulename-module失败”错误。但是

app-routing.module.ts

const routes: Routes = [
  { path: '', redirectTo:'login', pathMatch: 'full' },
  { path: 'parent', loadChildren: './layout/layout.module#LayoutModule'},
  { path: 'login', component: LoginComponent}
];

layout-routing.module.ts

const routes: Routes = [
      {
      path: '',
      component: LayoutComponent,
      children: [
          { path: 'dashboard', loadChildren: '../dashboard/dashboard.module#DashBoardModule'}, 
          { path: 'test', loadChildren: '../test/test.module#TestModule'}, 
          { path: '', redirectTo: 'dashboard', pathMatch: 'full' }
      ]
    }
];

layout.component.ts，

 navItems: NavItem[] = [
         {
          displayName: 'TEST',
          iconName: 'speaker_notes',
          route: 'test',
          children: [
            {
              displayName: 'Bulk Download',
              iconName: 'cloud_download',
              route: 'parent/test'
            }]
          }
        ]

在侧面菜单中的“测试”导航中，我在这里遇到错误。

任何人的帮助将不胜感激！