React Webpack 目标容器不是 DOM 元素

webpack在项目上启动服务器时React，控制台出现错误

目标容器不是 DOM 元素。

一般来说，这意味着没有容器用于ReactDOM渲染组件。

但是我在这里给出的元素

ReactDom.render(
  <App />,
  document.getElementById('content')
);

它存在。

这是配置文件webpack.config.js

var webpack = require('webpack');

module.exports = {
  entry: "./src/main.jsx",
  output: {
    path: __dirname + '/public/build/',
    publicPath: "build/",
    filename: "bundle.js"
  },
  module: {
    loaders: [
      {
        test: /\.css$/,
        loader: "style-loader!css-loader!autoprefixer-loader",
        exclude: [/node_modules/, /public/]
      },
      {
        test: /\.gif$/,
        loader: "url-loader?limit=10000&mimetype=image/gif"
      },
      {
        test: /\.jpg$/,
        loader: "url-loader?limit=10000&mimetype=image/jpg"
      },
      {
        test: /\.png$/,
        loader: "url-loader?limit=10000&mimetype=image/png"
      },
      {
        test: /\.svg$/,
        loader: "url-loader?limit=26000&mimetype=image/svg+xml"
      },
      {
        test: /\.jsx$/,
        loaders: ['react-hot-loader/webpack', 'babel-loader?presets[]=react'],
        exclude: [/node_modules/, /public/]
      },
      {
        test: /\.json$/,
        loader: "json-loader"
      }
    ]
  }
}

这是一个文件package.json。

{
  "name": "less2",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "jquery": "^3.3.1",
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "react-scripts": "1.1.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject",
    "devserver": "webpack-dev-server --debug --hot --devtool eval-source-map --output-pathinfo --watch --colors --inline --content-base public --port 8090 --host 0.0.0.0"
  },
  "devDependencies": {
    "autoprefixer-loader": "^3.2.0",
    "babel-core": "^6.26.0",
    "babel-loader": "^7.1.2",
    "babel-preset-env": "^1.6.1",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "css-loader": "^0.28.9",
    "file-loader": "^1.1.6",
    "json-loader": "^0.5.7",
    "postcss-loader": "^2.0.10",
    "react-hot-loader": "^3.1.3",
    "style-loader": "^0.19.1",
    "url-loader": "^0.6.2",
    "webpack": "^3.10.0",
    "webpack-dev-server": "^2.11.1"
  }
}

我不明白我在配置中错过了什么？