title: Can't fix the Electron React Boilerplate package error
body: <p>I'm using the <a href="https://github.com/electron-react-boilerplate/electron-react-boilerplate" rel="nofollow noreferrer">electron-react-boilerplate</a> to create a desktop application. And I'm using yarn package manager.</p>
  
  <p>I was compiling this application before 4 months. But now it can't be compiled.</p>
  
  <p>When I write <code>yarn package</code> command, it show this error:</p>
  
  <pre><code>yarn run v1.21.1
  $ yarn build &amp;&amp; electron-builder build --publish never
  $ concurrently "yarn build-main" "yarn build-renderer"
  $ cross-env NODE_ENV=production webpack --config ./configs/webpack.config.main.prod.babel.js --colors
  $ cross-env NODE_ENV=production webpack --config ./configs/webpack.config.renderer.prod.babel.js --colors
  [0] 
  [0] WARNING: We noticed you're using the `useBuiltIns` option without declaring a core-js version. Currently, we assume version 2.x when no version is passed. Since this default version will likely change in future versions of Babel, we recommend explicitly setting the core-js version you are using via the `corejs` option.
  [0]
  [0] You should also be sure that the version you pass to the `corejs` option matches the version specified in your `package.json`'s `dependencies` section. If it doesn't, you need to run one of the following commands:
  [0]
  [0]   npm install --save core-js@2    npm install --save core-js@3
  [0]   yarn add core-js@2              yarn add core-js@3
  [0]
  [1]
  [1] WARNING: We noticed you're using the `useBuiltIns` option without declaring a core-js version. Currently, we assume version 2.x when no version is passed. Since this default version will likely change in future versions of Babel, we recommend explicitly setting the core-js version you are using via the `corejs` option.
  [1]
  [1] You should also be sure that the version you pass to the `corejs` option matches the version specified in your `package.json`'s `dependencies` section. If it doesn't, you need to run one of the following commands:
  [1]
  [1]   npm install --save core-js@2    npm install --save core-js@3
  [1]   yarn add core-js@2              yarn add core-js@3
  [1]
  [0] Hash: bd31df9321aa201ea119
  [0] Version: webpack 4.41.6
  [0] Time: 630ms
  [0] Built at: 2020-02-23 21:50:09
  [0]                  Asset      Size  Chunks                   Chunk Names
  [0]     ./app/main.prod.js  2.19 KiB       0  [emitted]        main
  [0] ./app/main.prod.js.map  3.33 KiB       0  [emitted] [dev]  main
  [0] Entrypoint main = ./app/main.prod.js ./app/main.prod.js.map
  [0] [./app/main.dev.js] 2.99 KiB {0} [built]
  [0] [electron] external "electron" 42 bytes {0} [built]
  [0] [path] external "path" 42 bytes {0} [built]
  [0] [url] external "url" 42 bytes {0} [built]
  [0] yarn build-main exited with code 0
  [1] Hash: 71987f1d3c60720a4ec4
  [1] Version: webpack 4.41.6
  [1] Time: 493ms
  [1] Built at: 2020-02-23 21:50:10
  [1]                Asset      Size  Chunks                   Chunk Names
  [1]     renderer.prod.js     2 KiB       0  [emitted]        main
  [1] renderer.prod.js.map  8.96 KiB       0  [emitted] [dev]  main
  [1] Entrypoint main = renderer.prod.js renderer.prod.js.map
  [1] [./app/index.js] 2.64 KiB {0} [built]
  [1] [electron] external "electron" 42 bytes {0} [built]
  [1] [path] external "path" 42 bytes {0} [built]
  [1] [url] external "url" 42 bytes {0} [built]
  [1] yarn build-renderer exited with code 0
    • electron-builder version=20.44.4
    • loaded configuration file=package.json ("build" field)
    • writing effective config file=release\builder-effective-config.yaml
  SyntaxError: Unexpected token ﻿ in JSON at position 0
  SyntaxError: Unexpected token ﻿ in JSON at position 0
      at JSON.parse (&lt;anonymous&gt;)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:55:22
      at tryCatcher (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\bluebird\js\release\util.js:16:23)
      at Promise._settlePromiseFromHandler (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\bluebird\js\release\promise.js:547:31)
      at Promise._settlePromise (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\bluebird\js\release\promise.js:604:18)
      at Promise._settlePromise0 (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\bluebird\js\release\promise.js:649:10)
      at Promise._settlePromises (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\bluebird\js\release\promise.js:729:18)
      at Promise._fulfill (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\bluebird\js\release\promise.js:673:18)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\bluebird\js\release\nodeback.js:42:21
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\graceful-fs\graceful-fs.js:115:16
      at FSReqCallback.readFileAfterClose [as oncomplete] (internal/fs/read_file_context.js:61:3)
  From previous event:
      at readJson (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:55:6)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:224:61
      at Generator.next (&lt;anonymous&gt;)
      at callback (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\graceful-fs\polyfills.js:295:20)
      at FSReqCallback.oncomplete (fs.js:159:5)
  From previous event:
      at Collector.readChildPackage (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:206:90)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:191:69
  From previous event:
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:191:40
      at Generator.next (&lt;anonymous&gt;)
      at processImmediate (internal/timers.js:439:21)
  From previous event:
      at Collector.readInstalled (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:170:91)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:78:16
      at Generator.next (&lt;anonymous&gt;)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\graceful-fs\graceful-fs.js:115:16
      at FSReqCallback.readFileAfterClose [as oncomplete] (internal/fs/read_file_context.js:61:3)
  From previous event:
      at Collector.collect (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:76:28)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\packageDependencies.ts:47:44
      at Generator.next (&lt;anonymous&gt;)
      at _getProductionDependencies (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\packageDependencies.js:92:37)
      at getProductionDependencies (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\packageDependencies.js:83:37)
      at Lazy.&lt;anonymous&gt; (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:138:24)
      at Generator.next (&lt;anonymous&gt;)
      at Lazy.get value [as value] (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\lazy-val\src\main.ts:18:25)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\yarn.js:166:90
  From previous event:
      at _getProductionDependencies (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\packageDependencies.js:92:37)
      at getProductionDependencies (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\packageDependencies.js:83:37)
      at Lazy.&lt;anonymous&gt; (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:138:24)
      at Generator.next (&lt;anonymous&gt;)
  From previous event:
      at Lazy.get value [as value] (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\lazy-val\src\main.ts:18:25)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\yarn.js:166:90
      at Generator.next (&lt;anonymous&gt;)
  From previous event:
      at _rebuild (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\yarn.ts:179:5)
      at rebuild (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\yarn.js:163:19)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\util\yarn.ts:20:11
      at Generator.next (&lt;anonymous&gt;)
      at processImmediate (internal/timers.js:439:21)
  From previous event:
      at _installOrRebuild (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\yarn.js:71:28)
      at installOrRebuild (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\out\util\yarn.js:55:28)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:509:13
      at Generator.next (&lt;anonymous&gt;)
  From previous event:
      at Packager.installAppDependencies (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:470:70)    at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:420:20
      at Generator.next (&lt;anonymous&gt;)
  From previous event:
      at Packager.doBuild (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:396:24)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:366:57
      at Generator.next (&lt;anonymous&gt;)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\graceful-fs\graceful-fs.js:136:16
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\graceful-fs\graceful-fs.js:57:14
      at FSReqCallback.oncomplete (fs.js:146:23)
  From previous event:
      at Packager._build (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:335:133)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:331:23
      at Generator.next (&lt;anonymous&gt;)
      at processImmediate (internal/timers.js:439:21)
  From previous event:
      at Packager.build (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\packager.ts:288:14)
      at build (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\app-builder-lib\src\index.ts:59:28)
      at build (E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\electron-builder\src\builder.ts:228:10)
      at E:\Programming\htdocs\NodeJS\palettenzettel-4\node_modules\electron-builder\src\cli\cli.ts:49:19
  error Command failed with exit code 1.
  info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
  </code></pre>
  
  <p>And here is the <code>yarn package</code> command script:</p>
  
  <pre><code>"package": "yarn build &amp;&amp; electron-builder build --publish never",
  </code></pre>