Ionic 2 create new project with "ionic start helloworl blank--v2"

Error with start undefined
Error Initializing app: There was an error with the spawned command: npminstall
There was an error with the spawned command: npminstall
Caught exception:
undefined

my system information is-
You have been opted out of telemetry. To change this, run: cordova telemetry on.
6.3.1

Ionic CLI Version: 2.1.0
Ionic App Lib Version: 2.1.0-beta.1
OS:
Node Version: v4.6.0

ionic rc1 does not work with node 4