well this is really weird. Yesterday it worked. Today it worked. Then I got an NoMachine update alert, so I did the update and AFTER it I can’t connect and have the same error!
I checked nestat -a and utility TCPView but NONE of the ports mentioned in nxserver.log as used by another application are there as listening or established! Seems like an error in your application or something weird in my system blocking the NXTryBindLocal function :-\