This usually depends on the fact that, due to some system configuration, NX Server was unable to use the public key authentication method in order to successfully log the specific user on. SSHD logs might also show a "Connection closed..." error. You should check that:
The public key authentication method is enabled in your sshd configuration file.
The owner for the '~/.ssh/authorized_keys2' file and the '~/.ssh' directory is set to 'owner'.
The permissions for group and world users are not set on the same file and directory.
What to do if permissions of SSH authorized key filenames are different.
A possible example:
Looking in the sshd_config there's the line:
but in the nxserver configuration file there's a default value - authorized_keys2.
# Specify the location and file name of the SSH authorized keys.
#SSHAuthorizedKeys = "authorized_keys2"
Synchronize the filename of the SSH authorized keys. To do this, you can either set:
in sshd_config and restart sshd or set:
SSHAuthorizedKeys = "authorized_keys"
in server.cfg and node.cfg and then restart nxserver by executing following commands: