webpack-dev-server error on npm start

I am trying to run npm start on ng2-admin,all was working untill I did npm update to try to update the pacakages,

after that did npm start and have an error:

webpack-dev-server --config config/webpack.dev.js --progress --profile --watch --content-base src/
10% building modules 3/3 modules 0 activeError: listen EADDRINUSE 127.0.0.1:8080
at Object.exports._errnoException (util.js:1026:11)
at exports._exceptionWithHostPort (util.js:1049:20)
at Server._listen2 (net.js:1257:14)
at listen (net.js:1293:10)
at net.js:1403:9
at GetAddrInfoReqWrap.asyncCallback [as callback] (dns.js:62:16)
at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:81:10)
npm ERR! Darwin 15.5.0
npm ERR! argv "/Users/vm/versions/node/v6.9.1/bin/node" node/v6.9.1/bin/npm" "run" "server:dev"
npm ERR! node v6.9.1
npm ERR! npm v3.10.8
npm ERR! code ELIFECYCLE
npm ERR! ng2-admin@0.7.0 server:dev: webpack-dev-server --config config/webpack.dev.js --progress --profile --watch --content-base src/
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the ng2-admin@0.7.0 server:dev script 'webpack-dev-server --config config/webpack.dev.js --progress --profile --watch --content-base src/'.
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 ng2-admin package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! webpack-dev-server --config config/webpack.

回答1:

The relevant part of the error message is : listen EADDRINUSE 127.0.0.1:8080. That means that webpack-dev-server is trying to run on 127.0.0.1:8080, but the address and port is already in use.

Try opening your browser and typing 127.0.0.1:8080 into the address bar. Perhaps there is another server running on that port already. Run jobs to check for background processes.

回答2:

change dependency in package.json to

"webpack-dev-server": "2.1.0-beta.10", Instead of something like

"webpack-dev-server": "^2.1.0-beta.9",

run npm install or npm update afterwards.