Need help with getting NoMachine working on Ubuntu 14.04

I’m trying to get NoMachine working on a AWS EC2 instance with 14.04 Trusty Tahr.

I’ve used the instructions from:

• https://help.ubuntu.com/community/NomachineNX

• https://help.ubuntu.com/community/FreeNX

• http://javadude.wordpress.com/2012/12/05/running-ubuntu-12-04-desktop-on-ec2/

When I try to connect from my Mac using NoMachine 4.2.21, I get this error:

The connection with the server was lost.
Error is 54: Connection reset by peer.

When I use the OpenNX 0.16.0.729 client, I get a blank black screen.

Help.