求助~
版本号 element ui 2.2.1
vue 2.5.2
main.js:
import Vue from 'vue'
import ElementUI from 'element-ui'
import 'element-ui/lib/theme-chalk/index.css'
import Homepage from './components/homepage'
import router from './router'

Vue.use(ElementUI)
Vue.config.productionTip = false

/ eslint-disable no-new /
new Vue({
el: '#app',
router,
render: h => h(Homepage)
})

homepage.vue:
<template>
<div>

<el-container>
  <el-header>header</el-header>
  <el-main>main</el-main>
</el-container>  

</div>
</template>
控制台没有报错。