Hi Ricardo,
Firstly, you should check the following article: https://www.nomachine.com/AR11K00751 which explains why this message “The NoMachine service is not available on host…” appears and what you can do. Seeing that you are using an old version of NX, you could try this article here:
http://https://www.nomachine.com/AR04J00627
Secondly, it would be better if you used official packages from NoMachine on your server 🙂 To run a virtual desktop you could install the Workstation product. Unfortunately, we aren’t responsible for the FreeNX packages you are using.