Class constructor FileManager cannot be invoked without 'new' in undefined (line undefined, column undefined)

[LuoRiWuSheng]

Version

3.10.0

Environment info

  System:
    OS: Windows 10
    CPU: (4) x64 Intel(R) Core(TM) i5-4210M CPU @ 2.60GHz
  Binaries:
    Node: 10.16.1 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.16.0 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 6.9.0 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: 44.17763.1.0
  npmPackages:
    @vue/babel-helper-vue-jsx-merge-props:  1.0.0
    @vue/babel-plugin-transform-vue-jsx:  1.0.0
    @vue/babel-preset-app:  3.10.0
    @vue/babel-preset-jsx:  1.1.0
    @vue/babel-sugar-functional-vue:  1.0.0
    @vue/babel-sugar-inject-h:  1.0.0
    @vue/babel-sugar-v-model:  1.0.0
    @vue/babel-sugar-v-on:  1.1.0
    @vue/cli-overlay:  3.10.0
    @vue/cli-plugin-babel: ^3.10.0 => 3.10.0
    @vue/cli-service: ^3.10.0 => 3.10.0
    @vue/cli-shared-utils:  3.10.0
    @vue/component-compiler-utils:  2.6.0 (3.0.0)
    @vue/preload-webpack-plugin:  1.1.1
    @vue/web-component-wrapper:  1.2.0
    eslint-plugin-vue: ^5.2.3 => 5.2.3
    vue: ^2.6.10 => 2.6.10
    vue-eslint-parser:  5.0.0
    vue-hot-reload-api:  2.3.3
    vue-loader:  15.7.1
    vue-router: ^3.0.3 => 3.1.2
    vue-style-loader:  4.1.2
    vue-template-compiler: ^2.6.10 => 2.6.10
    vue-template-es2015-compiler:  1.9.1
    vuex: ^3.0.1 => 3.1.1
  npmGlobalPackages:
    @vue/cli: Not Found

Steps to reproduce

vue create h
cd h
yarn serve

What is expected?

项目能够跑起来

What is actually happening?

报错，无法运行

[keveon]

可以看看这个 #4449

[sodatea]

yarn add less-loader@5 -D

[JulCyan]

yarn add less-loader@5 -D

Really useful

[LuoRiWuSheng]

yarn add less-loader@5 -D

Really useful

ok i'll try。
Thank you very much.