Netbackup-error: vmware credential validation failed

So, this is a new setup where you need to configure VMware backups?

Have you tested hostname lookup at OS level between master and ESX/vCentre and between backup host and ESX/vCentre? 
Can you ping ESX/vCentre hostname from cmd on master and backup host?

Hello,

it is a new ESX server, it is not integrated into the Vcenter, so I want to configure ESX

from the NetBackup server i can ping the ESX server and even the hostname from cmd

login to the ESXi host and enter the command hostname and see what is the name it is returning.

make sure the name that is displaying in hostname command output is able to resolve from backup host and you are using the same name to enter the credentials.

Which version is ESX server? Have you verified compatibility?

Firewall between backup host and ESX?

If possible, install vSphere Client on the backup host and see if you can login with the same credentials.

it is the same name.

ESX Server Version: 5.0

the Firewall between backup host and ESX is desable

i install vSphere Client on the backup host and I can login with the same credentials

Maybe you can tell us step-by-step how you have done this config.

Do you have Enterprise Client license on the master?

Have you added backup host in Host Properties?

Maybe this TN will help: 
http://www.symantec.com/docs/HOWTO70882 

Or this one to use cmd: 
http://www.symantec.com/docs/TECH68837 

PS: 
You have not mentioned or selected the OS on your master.
If this is W2008 or W2012, ensure UAC is disabled or else open NBU Admin Console with right-click, Run as Administrator.

thinkyou