$ npm run serve
> [email protected] serve D:\www\zcsys\manage
> vue-cli-service serve
INFO Starting development server...
10% building 2/2 modules 0 active ERROR TypeError: Cannot read property 'upgrade' of undefined
TypeError: Cannot read property 'upgrade' of undefined
at Server. (D:\www\zcsys\manage\node_modules\webpack-dev-server\lib\Server.js:720:47)
at Array.forEach ()
at new Server (D:\www\zcsys\manage\node_modules\webpack-dev-server\lib\Server.js:719:22)
at serve (D:\www\zcsys\manage\node_modules\@vue\cli-service\lib\commands\serve.js:138:20)
at process._tickCallback (internal/process/next_tick.js:68:7)
at Function.Module.runMain (internal/modules/cjs/loader.js:757:11)
at startup (internal/bootstrap/node.js:283:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] serve: `vue-cli-service serve`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] serve script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\Administrator\AppData\Roaming\npm-cache\_logs\2019-06-03T01_52_19_142Z-debug.log
