It could be a network connection proxy issue, that is failing to fetch plugins.
Can you try "upgrading" the HTML5 project that you created by clicking on the "Upgrade" button in the project settings page
Thanks for your answer.
Upgrading worked but if I try to add a Cordova plugin, I obtain this error too :
Unexpected call to process.exit()
I tried to disable Windows Firewall, issue was still here.
Marcelo -- did you upgrade to Windows 10 after the XDK was already installed on your system? If so, you need to reinstall the XDK (no need to uninstall, just go to http://xdk.intel.com and download the installer and install it a second time).