VAS Preflight Diagnostic Tool error: Internal host error, bad domain name or error in /etc/res (4345528)

Vintela Authentication Services (VAS) Preflight Diagnostic Tool fails with the following error message:

"Setting up VAS context and environment...
ERROR: Internal host error, bad domain name or error in /etc/resolv.conf?
Relaunch preflight with a valid domain name."

Incorrect Domain Name System (DNS) setup.

There is a missing DNS entry in the nsswitch.conf file on the hosts line.

1. Edit /etc/nsswitch.conf file

2. Change the line that says "hosts: files" to "hosts: files dns"