Webpack vue cli从v3升级到v4会中断生成过程，并出现线程加载程序错误：无法读取属性'；选项'；未定义的

我刚刚将vue cli从v3升级到v4。开发模式有效！但是，生成过程错误可以通过以下方式消除：

 error  in ./src/App/components/AppLayout.vue?vue&type=script&lang=js&

Module build failed (from ./node_modules/thread-loader/dist/cjs.js):
Thread Loader (Worker 0)
Cannot read property 'options' of undefined
    at PoolWorker.fromErrorObj (/home/vsonline/workspace/node_modules/thread-loader/dist/WorkerPool.js:26
2:12)
    at /home/vsonline/workspace/node_modules/thread-loader/dist/WorkerPool.js:204:29
    at mapSeries (/home/vsonline/workspace/node_modules/neo-async/async.js:3625:14)
    at PoolWorker.onWorkerMessage (/home/vsonline/workspace/node_modules/thread-loader/dist/WorkerPool.js
:170:35)
    at /home/vsonline/workspace/node_modules/thread-loader/dist/WorkerPool.js:152:14
    at Socket.onChunk (/home/vsonline/workspace/node_modules/thread-loader/dist/readBuffer.js:36:9)
    at Object.loader (/home/vsonline/workspace/node_modules/vue-inheritance-loader/src/index.js:26:32)

 @ ./src/App/components/AppLayout.vue?vue&type=script&lang=js& 1:0-458 1:474-477 1:479-934 1:479-934
 @ ./src/App/components/AppLayout.vue
 @ ./src/App/router/index.js
 @ ./src/main.ts
 @ multi ./src/main.ts

---

vue.config.js

：

parallel:false

，允许我避免这个问题，非常感谢！