Hi,
there are two options for users of the earlier NX 3.5.0 client package. You can install the free NoMachine package (which functions as both a server and a client) or you can use the Enterprise Client as you did 🙂 This is also free.
The reason you are getting a “an evaluation expired” message is probably due to a previous package (e.g. the Workstation perhaps?) that you had installed on your remote machine. I suggest uninstalling the nomachine-4.0.369-1.x86_64 package from your server host, removing the directory and reinstalling.