npm ERR! code ERESOLVE npm ERR! ERESOLVE unable to resolve dependency tree npm ERR! npm ERR! While resolving: routerdemo@0.1.0 npm ERR! Found: vue@2.6.14 npm ERR! node_modules/vue npm ERR! vue@"^2.6.14" from the root project npm ERR! npm ERR! Could not resolve dependency: npm ERR! peer vue@"^3.2.0" from vue-router@4.0.15 npm ERR! node_modules/vue-router npm ERR! vue-router@"*" 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 D:\Node.js\node_cache\eresolve-report.txt for a full report. npm ERR! A complete log of this run can be found in: 安装失败的原因是：我安装的是Choose a version of Vue.js that you want to start the project with 2.x ，vue2.x版本兼用不了最新的版本的router，即这条命令（npm install vue-router -S），它默认安装高版本，解决方法：npm i vue-router@3.5.2（router版本） -S，用低版本即可