Sharepoint 2013 backup failed

Dear All,

Kindly note I'm using Netbackup 7.6.0.2 clinet installed on sharepoint 2013 servers [ 2 servers APP, and 2 Server DB ] I've applied all the required configurations mentioned in "Symantec NetBackup™ for Microsoft SharePoint Server Administrator’s Guide" documentation  but we still have the error "Unable to validate username/password. Error 1300:", on Client properties

Thanks