"loose": true is not fixing Support for the experimental syntax 'classProperties' isn't currently enabled

I am using plugin-proposal-class-propterties and it works, here is my JSON configuration file .babelrc

{  "presets": ["@babel/preset-env"],  "plugins": [    [      "@babel/plugin-proposal-class-properties",      {"loose": true}    ]  ]}

Try making a file babel.config.js and using module.exports to export the configuration. I also believe you don't require the loose option:

babel.config.js:

module.exports = {  presets: ["@babel/preset-env", "@babel/preset-react"],  plugins: ["@babel/plugin-proposal-class-propterties"]};

you must install

npm install @babel/core @babel/plugin-proposal-class-properties@babel/preset-env @babel/preset-react babel-loader

and

change entry and output

const path = require('path')        module.exports = {  entry: path.resolve(__dirname,'src', 'app.js'),  output: {    path: path.resolve(__dirname, "public","dist",'javascript'),    filename: 'bundle.js'  },  module: {    rules: [      {        test: /\.(jsx|js)$/,        exclude: /node_modules/,        use: [{          loader: 'babel-loader',          options: {            presets: [              ['@babel/preset-env', {                "targets": "defaults"              }],              '@babel/preset-react'            ],            plugins: [              "@babel/plugin-proposal-class-properties"            ]          }        }]      }    ]  }}