Hello Marco,

In my opinion it's an issue related to the nodejs version.

Install nodejs 4.x (choose an LTS) and run "node server" again (I'm not sure if you need to run again "npm install" before).

By the way, on my Ubuntu 16.04 with Nodejs 4.x it works, so you can try to reinstall from scratch having node 4.

Ciao, Fabio.