Syntax Error: TypeError: this.getOptions is not a function

今天安装less-loader提示如下报错

ERROR  Failed to compile with 1 error                                                                                    9:15:24
error  in ./src/App.vue?vue&type=style&index=0&id=7ba5bd90&lang=less&scoped=true&

Syntax Error: TypeError: this.getOptions is not a function

 @ ./node_modules/vue-style-loader??ref--11-oneOf-1-0!./node_modules/css-loader/dist/cjs.js??ref--11-oneOf-1-1!./node_modules/vue-loader/lib/loaders/stylePostLoader.js!./node_modules/postcss-loader/src??ref--11-oneOf-1-2!./node_modules/less-loader/dist/cjs.js??ref--11-oneOf-1-3!./node_modules/cache-loader/dist/cjs.js??ref--1-0!./node_modules/vue-loader/lib??vue-loader-options!./src/App.vue?vue&type=style&index=0&id=7ba5bd90&lang=less&scoped=true& 4:14-443 15:3-20:5 16:22-451
 @ ./src/App.vue?vue&type=style&index=0&id=7ba5bd90&lang=less&scoped=true&

发现默认安装的less-loader版本号太高了， 解决： npm uninstall less-loader

npm install less-loader@6.0.0 -D