How to fix 'Plugin/Preset files are not allowe

Question

I am running through a React tutorial and have hit this problem when I run npm run on my project. The larger error code is:

ERROR in ./src/index.jsx Module build failed (from ./node_modules/babel-loader/lib/index.js): Error: Plugin/Preset files are not allowed to export objects, only functions. In /S8L27nodeproject/node_modules/babel-preset-react/lib/index.js

Looking at similar questions I thought my versions of Babel were not up-top-date, seeing as babel-loader is a different version to the others, but when I run npm outdated they appear fine.

My package.json file is:

{
  "name": "s8l27nodeproject",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "webpack -p",
    "start": "node ./node_modules/webpack-dev-server/bin/webpack-dev-server.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "babel-core": "^6.26.3",
    "babel-loader": "^8.0.4",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "babel-preset-stage-1": "^6.24.1",
    "react": "^16.6.0",
    "react-dom": "^16.6.0",
    "webpack": "^4.25.1",
    "webpack-dev-server": "^3.1.10"
  },
  "devDependencies": {
    "@babel/core": "^7.1.5",
    "webpack-cli": "^3.1.2"
  }
}

Whilst my webpack.config.js file is:

module.exports = {
    entry: [
        './src/index.jsx'
    ],
    output: {
        filename: './bundle.js'
    },
    module: {
        rules: [{
            exclude: /node_modules/,
            loader: 'babel-loader'
        }]
    }
}

Would anyone know what I could do to fix this problem?