1.安装less时报错了,原因是安装的版本太高了

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! 
npm ERR! While resolving: ceshi@1.0.0
npm ERR! Found: webpack@3.12.0       
npm ERR! node_modules/webpack        
npm ERR!   dev webpack@"^3.6.0" from the root project
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer webpack@"^5.0.0" from less-loader@8.0.0
npm ERR! node_modules/less-loader
npm ERR!   less-loader@"*" from the root project
npm ERR! 
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
npm ERR!
npm ERR! See C:\Users\59129\AppData\Local\npm-cache\eresolve-report.txt for a full report.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\59129\AppData\Local\npm-cache\_logs\2021-03-19T09_05_44_385Z-debug.log

2.报错原因 less 本版太高需要降低版本，执行代码

先移除之前版本：npm uninstall less-loader
下载指定版本：npm install less-loader@5.0.0 -D

3.重启代码就可以了，若还是报错可移除文件node_modules，重新下载cnpm install