We would definitely need more inputs from your side. What changed in the environment after which this issue surfaced? Is the problem for only 1 user or all the users? Have you tried running jnbSA as root?
What are the messages displayed on screen and nbjlogs when you run jnbSA?
I was playing with DNS a bit an simulated the same issue in my environment it was apparently tied to the fact that Java was unable to resolve host names of the client where the console was being run and the NBU server at some point.
