By default, the NX server 3.5.0 is configured to allow 20 concurrent connections. This means that, even in case of a subscription allowing unlimited concurrent sessions, when the 21st concurrent user tries to run a session, he/she will get the following message:
Reached the maximum number of concurrent sessions on this server
To increase the number of concurrent connections according to your needs, please edit the following configuration key in the /usr/NX/etc/server.cfg file:
#SessionLimit = "20"
You will need to uncomment the line and change the sessions number to a reasonable limit for your server. ie.
SessionLimit="40"
You may also wish to consult the NX Server Administrator's Guide for other configurable options. The guide is available at the following link:
http://www.nomachine.com/DT12I00014
Other references
For NoMachine v. 4 or later please read here:
https://www.nomachine.com/AR08M00858
