我在Angular 4应用程序中运行服务时遇到这些错误

Question

log
close 
socket/sock.onclose
../../../../sockjs-client/lib/event/eventtarget.js/EventTarget.prototype.dispatchEvent 
../../../../sockjs-client/lib/main.js/</SockJS.prototype._close/<  in  'http://localhost:4200/vendor.bundle.js'

../../../../zone.js/dist/zone.js/</</ZoneDelegate.prototype.invokeTask 
../../../../zone.js/dist/zone.js/</</Zone.prototype.runTask 
../../../../zone.js/dist/zone.js/</</ZoneTask.invokeTask 

ZoneTask / this.invoke 计时器＆＃39; http://localhost:4200/polyfills.bundle.js＆＃39;