React-MobX Error: The 'decorators' plugin requires a 'decoratorsBeforeExport' option, whose value must be a boolean : <p>I get the following error: If you are migrating from Babylon/Babel 6 or want to use the old decorators proposal, you should use the 'decorators-legacy' plugin instead of 'decorators'.</p>

<p><strong>package.json</strong></p>

<pre><code>"@babel/plugin-proposal-decorators": {
      "version": "7.1.2",
      "resolved": "https://registry.npmjs.org/@babel/plugin-proposal-decorators/-/plugin-proposal-decorators-7.1.2.tgz",
      "integrity": "sha512-YooynBO6PmBgHvAd0fl5e5Tq/a0pEC6RqF62ouafme8FzdIVH41Mz/u1dn8fFVm4jzEJ+g/MsOxouwybJPuP8Q==",
      "requires": {
        "@babel/helper-plugin-utils": "^7.0.0",
        "@babel/helper-replace-supers": "^7.1.0",
        "@babel/helper-split-export-declaration": "^7.0.0",
        "@babel/plugin-syntax-decorators": "^7.1.0"
      }
    },

 "@babel/plugin-syntax-decorators": {
      "version": "7.1.0",
      "resolved": "https://registry.npmjs.org/@babel/plugin-syntax-decorators/-/plugin-syntax-decorators-7.1.0.tgz",
      "integrity": "sha512-uQvRSbgQ0nQg3jsmIixXXDCgSpkBolJ9X7NYThMKCcjvE8dN2uWJUzTUNNAeuKOjARTd+wUQV0ztXpgunZYKzQ==",
      "requires": {
        "@babel/helper-plugin-utils": "^7.0.0"
      }
    },

"babel-plugin-syntax-decorators": {
      "version": "6.13.0",
      "resolved": "http://registry.npmjs.org/babel-plugin-syntax-decorators/-/babel-plugin-syntax-decorators-6.13.0.tgz",
      "integrity": "sha1-MSVjtNvePMgGzuPkFszurd0RrAs=",
      "dev": true
    },
    "babel-plugin-transform-decorators-legacy": {
      "version": "1.3.5",
      "resolved": "https://registry.npmjs.org/babel-plugin-transform-decorators-legacy/-/babel-plugin-transform-decorators-legacy-1.3.5.tgz",
      "integrity": "sha512-jYHwjzRXRelYQ1uGm353zNzf3QmtdCfvJbuYTZ4gKveK7M9H1fs3a5AKdY1JUDl0z97E30ukORW1dzhWvsabtA==",
      "dev": true,
      "requires": {
        "babel-plugin-syntax-decorators": "^6.1.18",
        "babel-runtime": "^6.2.0",
        "babel-template": "^6.3.0"
      }
    },
"requires": {
     "@babel/plugin-proposal-decorators": "7.1.2",
}
</code></pre>

<p><strong>tsconfig.json</strong></p>

<pre><code>{
    "compilerOptions": {
        "experimentalDecorators": true,
        "allowJs": true
    }
}
</code></pre>
