React Uncaught Error：目标容器不是DOM元素[重复]

Question

这个问题在这里已有答案：

Invariant Violation: _registerComponent(…): Target container is not a DOM element 11个答案

我最近创建了我的webpack配置文件：

const path = require("path");

const SRC_DIR = path.join(__dirname, "/client/src");
const DIST_DIR = path.join(__dirname, "/client/dist");

module.exports = {
  entry: `${SRC_DIR}/index.jsx`,
  output: {
    filename: "bundle.js",
    path: DIST_DIR
  },
  module: {
    rules: [
      {
        test: /.jsx?$/,
        include: SRC_DIR,
        exclude: /node_modules/,
        loader: "babel-loader",
        query: {
          presets: ["react", "es2015"]
        }
      }
    ]
  },
  mode: "development"
};

这个很好，并捆绑了jsx文件：

import React from "react";
import ReactDOM from "react-dom";

class MainApp extends React.Component {
  render() {
    return (
      <div className="content">
        <h1>Hello World</h1>
      </div>
    );
  }
}

ReactDOM.render(<MainApp />, document.getElementById("app"));

现在在html文件中我包含了带有div id应用程序的bundle文件。

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>REACT TEST</title>
  <script src="./bundle.js"></script>
</head>

<body>
  <div id="app"></div>
</body>

</html>

当我试图运行它似乎它不起作用，我得到错误：

Uncaught Error: Target container is not a DOM element.
    at invariant (invariant.js:42)
    at legacyRenderSubtreeIntoContainer (react-dom.development.js:17116)
    at Object.render (react-dom.development.js:17195)
    at eval (index.jsx:48)
    at Object../client/src/index.jsx (bundle.js:97)
    at __webpack_require__ (bundle.js:20)
    at bundle.js:84
    at bundle.js:87
invariant   @   invariant.js:42

我在这里错过了什么？为什么我收到此错误？

Answer 1

另一答案