vue.js - npm run dev reported an error. I don't know if it is a problem with the version of node.js or npm installed.

Question

vue-hnn@2.0.0 dev /Users/yaomengfei/Desktop/htweb
node build/dev-server.js

events.js:160

  throw er; // Unhandled 'error' event
  ^

Error: listen EADDRINUSE :::8030

at Object.exports._errnoException (util.js:1022:11)
at exports._exceptionWithHostPort (util.js:1045:20)
at Server._listen2 (net.js:1262:14)
at listen (net.js:1298:10)
at Server.listen (net.js:1376:9)
at Function.listen (/Users/yaomengfei/Desktop/htweb/node_modules/express/lib/application.js:618:24)
at Object.<anonymous> (/Users/yaomengfei/Desktop/htweb/build/dev-server.js:59:22)
at Module._compile (module.js:571:32)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:488:32)
at tryModuleLoad (module.js:447:12)
at Function.Module._load (module.js:439:3)
at Module.runMain (module.js:605:10)
at run (bootstrap_node.js:420:7)
at startup (bootstrap_node.js:139:9)
at bootstrap_node.js:535:3

npm ERR! Darwin 16.6.0
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "run" "dev"
npm ERR! node v7.3.0
npm ERR! npm v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! vue-hnn@2.0.0 dev: node build/dev-server.js
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the vue-hnn@2.0.0 dev script 'node build/dev-server.js'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the vue-hnn package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! node build/dev-server.js
npm ERR! You can get information on how to open an issue for this project with:
npm ERR! npm bugs vue-hnn
npm ERR! Or if that isn't available, you can get their info via:
npm ERR! npm owner ls vue-hnn
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:

Answer 1

The reason for the error is that you have already used the port 8030