Fresh git clone stucks after npm run start #1

I made a git clone, then npm install, then npm run start
When I go to the url, which is http://localhost:4200/
it shows me the "loading ..." message and the error in the console is the following:

zone.js:101 GET http://localhost:4200/traceur 404 (Not Found)

Unhandled Promise rejection: Error: XHR error (404 Not Found) loading http://localhost:4200/traceur
at XMLHttpRequest.wrapFn as _onreadystatechange
at ZoneDelegate.invokeTask (http://localhost:4200/vendor/zone.js/dist/zone.js:356:38)
at Zone.runTask (http://localhost:4200/vendor/zone.js/dist/zone.js:256:48)
at XMLHttpRequest.ZoneTask.invoke (http://localhost:4200/vendor/zone.js/dist/zone.js:423:34)
Error loading http://localhost:4200/traceur
Error loading http://localhost:4200/vendor/@angular2-material/button/button.js as "@angular2-material/button" from http://localhost:4200/app/mail.module.js ; Zone: ; Task: Promise.then ; Value: Error: Error: XHR error (404 Not Found) loading http://localhost:4200/traceur(…)

I run it on windows 8 with npm 3.10.5 and nodejs v4.4.7