Access to the Nimsoft Monitor Server page at: http://<hostname>:8080 worked fine, but after clicking on the Nimsoft Monitor Admin Console link, a popup error occurred:
ServerErrorException - Internal Server Error: '(4) not found, Received status (4) on response (for sendRcv) for cmd = 'hubsec_list' name = 'null''
<Please see attached file for image>

Solution:
The user trying to login did not exist under Security->User Administration in the Infrastructure Manager (IM).
Also make sure that the administrator userid that already exists or is newly created is associated with the "Default profile" named "default."
Once the user was added no further errors occurred upon login to the web admin console.