"The remote proxy closed the connection while negotiating the session. This may be due to the wrong authentication credentials passed to the server"I checked /etc/hosts and found localhost entry intact also checked the /tmp directory it was having the full access. Then, I did the trick and removed .nx directory completely from my home directory. This trick did work and sorted out the problem.
NX Free Edition provides only 2 concurrent connections at any one time will be allowed, and up to 2 user names is permitted. In this case, who has the access, how to add and remove the user makes sense. Following commands may help you to do so. (You need root access to run these command). Find the NX home directory (in my case it was /usr/NX) and run the following command:
To know who has the NX access:
/usr/NX nxserver --userlistTo add the user:
/usr/NX nxserver --useraddTo delete the existing user:
/usr/NX nxserver --userdel