element-ui项目无法运行部分内容，报错：The message port closed before a response was received.

一、问题描述:在App.vue中引入index.vue报错，无法运行出页面主体部分，可运行出头部及导航栏

二、第一种引入方式及报错：在App.vue中插入标签Index
1.项目系统结构：

2.源码

###### 

App.vue文件：

<template>
  <div id="app">
    <Index></Index>

  </div>
</template>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
}

#nav {
  padding: 30px;
}

#nav a {
  font-weight: bold;
  color: #2c3e50;
}

#nav a.router-link-exact-active {
  color: #42b983;
}
</style>
<script>
  import Index from "./components/Index";
  export default {
    name:'App',
    components: {Index}
  }
</script>

main.js文件：

import Vue from 'vue'
import App from './App.vue'
import router from './router'
import ElementUI from 'element-ui';
import 'element-ui/lib/theme-chalk/index.css';
Vue.config.productionTip = false
Vue.use(ElementUI);
new Vue({
  router,
  render: h => h(App)
}).$mount('#app')

Index.vue文件：

<template>
    <el-container style="height: 500px; border: 1px solid #eee">
        <el-aside width="200px" style="background-color: rgb(238, 241, 246)">
            <el-menu :default-openeds="['1', '3']">
                <el-submenu index="1">
                    <template slot="title"><i class="el-icon-message"></i>导航一</template>
                    <el-menu-item-group>
                        <template slot="title">分组一</template>
                        <el-menu-item index="1-1">选项1</el-menu-item>
                        <el-menu-item index="1-2">选项2</el-menu-item>
                    </el-menu-item-group>
                    <el-menu-item-group title="分组2">
                        <el-menu-item index="1-3">选项3</el-menu-item>
                    </el-menu-item-group>
                    <el-submenu index="1-4">
                        <template slot="title">选项4</template>
                        <el-menu-item index="1-4-1">选项4-1</el-menu-item>
                    </el-submenu>
                </el-submenu>
                <el-submenu index="2">
                    <template slot="title"><i class="el-icon-menu"></i>导航二</template>
                    <el-menu-item-group>
                        <template slot="title">分组一</template>
                        <el-menu-item index="2-1">选项1</el-menu-item>
                        <el-menu-item index="2-2">选项2</el-menu-item>
                    </el-menu-item-group>
                    <el-menu-item-group title="分组2">
                        <el-menu-item index="2-3">选项3</el-menu-item>
                    </el-menu-item-group>
                    <el-submenu index="2-4">
                        <template slot="title">选项4</template>
                        <el-menu-item index="2-4-1">选项4-1</el-menu-item>
                    </el-submenu>
                </el-submenu>
                <el-submenu index="3">
                    <template slot="title"><i class="el-icon-setting"></i>导航三</template>
                    <el-menu-item-group>
                        <template slot="title">分组一</template>
                        <el-menu-item index="3-1">选项1</el-menu-item>
                        <el-menu-item index="3-2">选项2</el-menu-item>
                    </el-menu-item-group>
                    <el-menu-item-group title="分组2">
                        <el-menu-item index="3-3">选项3</el-menu-item>
                    </el-menu-item-group>
                    <el-submenu index="3-4">
                        <template slot="title">选项4</template>
                        <el-menu-item index="3-4-1">选项4-1</el-menu-item>
                    </el-submenu>
                </el-submenu>
            </el-menu>
        </el-aside>

        <el-container>
            <el-header style="text-align: right; font-size: 12px">
                <el-dropdown>
                    <i class="el-icon-setting" style="margin-right: 15px"></i>
                    <el-dropdown-menu slot="dropdown">
                        <el-dropdown-item>查看</el-dropdown-item>
                        <el-dropdown-item>新增</el-dropdown-item>
                        <el-dropdown-item>删除</el-dropdown-item>
                    </el-dropdown-menu>
                </el-dropdown>
                <span>王小虎</span>
            </el-header>

            <el-main>
                <el-table :data="tableData">
                    <el-table-column prop="date" label="日期" width="140">
                    </el-table-column>
                    <el-table-column prop="name" label="姓名" width="120">
                    </el-table-column>
                    <el-table-column prop="address" label="地址">
                    </el-table-column>
                </el-table>
            </el-main>
        </el-container>
    </el-container>
</template>

<script>
    export default {
        name: "Index",
        data() {
            const item = {
                date: '2016-05-02',
                name: '王小虎',
                address: '上海市普陀区金沙江路 1518 弄'
            };
            return {
                tableData: Array(20).fill(item)
            }
        }
    }
</script>

<style scoped>
    .el-header {
        background-color: #B3C0D1;
        color: #333;
        line-height: 60px;
    }

    .el-aside {
        color: #333;
    }
</style>

Index.js文件

import Vue from 'vue'
import VueRouter from 'vue-router'
import Home from '../views/Home.vue'

Vue.use(VueRouter)

const routes = [
  {
    path: '/',
    name: 'Home',
    component: Home
  },
  {
    path: '/about',
    name: 'About',
    // route level code-splitting
    // this generates a separate chunk (about.[hash].js) for this route
    // which is lazy-loaded when the route is visited.
    component: () => import(/* webpackChunkName: "about" */ '../views/About.vue')
  }
]

const router = new VueRouter({
  routes
})

export default router

3.运行结果及报错

三、第二种引入方式及报错：在App.vue中通过router-views引入Index
1.项目系统结构：

2.源码：

######

App.vue文件：

<template>
  <div id="app">
   111
    <router-view/>
  </div>
</template>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
}

#nav {
  padding: 30px;
}

#nav a {
  font-weight: bold;
  color: #2c3e50;
}

#nav a.router-link-exact-active {
  color: #42b983;
}
</style>
<!--<script>-->
<!--  import Index from "./views/Index";-->
<!--  export default {-->
<!--    name:'App',-->
<!--    components: {Index}-->
<!--  }-->
<!--</script>-->


index.js文件

import Vue from 'vue'
import VueRouter from 'vue-router'

import Index from '../views/Index.vue'

Vue.use(VueRouter)

const routes = [

  {
    path: '/',
    name: 'Index',
    component: Index
  }
]

const router = new VueRouter({
  routes
})

export default router

Index.vue文件：

<template>
    <el-container style="height: 500px; border: 1px solid #eee">
        <el-aside width="200px" style="background-color: rgb(238, 241, 246)">
            <el-menu :default-openeds="['1', '3']">
                <el-submenu index="1">
                    <template slot="title"><i class="el-icon-message"></i>导航一</template>
                    <el-menu-item-group>
                        <template slot="title">分组一</template>
                        <el-menu-item index="1-1">选项1</el-menu-item>
                        <el-menu-item index="1-2">选项2</el-menu-item>
                    </el-menu-item-group>
                    <el-menu-item-group title="分组2">
                        <el-menu-item index="1-3">选项3</el-menu-item>
                    </el-menu-item-group>
                    <el-submenu index="1-4">
                        <template slot="title">选项4</template>
                        <el-menu-item index="1-4-1">选项4-1</el-menu-item>
                    </el-submenu>
                </el-submenu>
                <el-submenu index="2">
                    <template slot="title"><i class="el-icon-menu"></i>导航二</template>
                    <el-menu-item-group>
                        <template slot="title">分组一</template>
                        <el-menu-item index="2-1">选项1</el-menu-item>
                        <el-menu-item index="2-2">选项2</el-menu-item>
                    </el-menu-item-group>
                    <el-menu-item-group title="分组2">
                        <el-menu-item index="2-3">选项3</el-menu-item>
                    </el-menu-item-group>
                    <el-submenu index="2-4">
                        <template slot="title">选项4</template>
                        <el-menu-item index="2-4-1">选项4-1</el-menu-item>
                    </el-submenu>
                </el-submenu>
                <el-submenu index="3">
                    <template slot="title"><i class="el-icon-setting"></i>导航三</template>
                    <el-menu-item-group>
                        <template slot="title">分组一</template>
                        <el-menu-item index="3-1">选项1</el-menu-item>
                        <el-menu-item index="3-2">选项2</el-menu-item>
                    </el-menu-item-group>
                    <el-menu-item-group title="分组2">
                        <el-menu-item index="3-3">选项3</el-menu-item>
                    </el-menu-item-group>
                    <el-submenu index="3-4">
                        <template slot="title">选项4</template>
                        <el-menu-item index="3-4-1">选项4-1</el-menu-item>
                    </el-submenu>
                </el-submenu>
            </el-menu>
        </el-aside>

        <el-container>
            <el-header style="text-align: right; font-size: 12px">
                <el-dropdown>
                    <i class="el-icon-setting" style="margin-right: 15px"></i>
                    <el-dropdown-menu slot="dropdown">
                        <el-dropdown-item>查看</el-dropdown-item>
                        <el-dropdown-item>新增</el-dropdown-item>
                        <el-dropdown-item>删除</el-dropdown-item>
                    </el-dropdown-menu>
                </el-dropdown>
                <span>王小虎</span>
            </el-header>

            <el-main>
                <el-table :data="tableData">
                    <el-table-column prop="date" label="日期" width="140">
                    </el-table-column>
                    <el-table-column prop="name" label="姓名" width="120">
                    </el-table-column>
                    <el-table-column prop="address" label="地址">
                    </el-table-column>
                </el-table>
            </el-main>
        </el-container>
    </el-container>
</template>

<script>
    export default {
        name: "Index",
        data() {
            const item = {
                date: '2016-05-02',
                name: '王小虎',
                address: '上海市普陀区金沙江路 1518 弄'
            };
            return {
                tableData: Array(20).fill(item)
            }
        }
    }
</script>

<style scoped>
    .el-header {
        background-color: #B3C0D1;
        color: #333;
        line-height: 60px;
    }

    .el-aside {
        color: #333;
    }
</style>

3.运行结果及报错

四、尝试的解决思路
1.换浏览器，将360换成Edge、Chrome未解决
2.怀疑是第三方应用扩展导致，卸载腾讯huiyi未解决。
3.运行仓库管理系统源码，首页未正常显示左侧导航栏

别人的正常导航栏

是不是装了什么扩展程序，都先关闭了试试