KERBEROS_V4 rejected as an authentication type error

Hi am just trying to FTP am while doing so am getting the "KERBEROS_V4 rejected as an authentication type" error.Please let me know what should be done to avoid this error.

The code is

#!/bin/ksh -x
#
# Get new files only ftp
#
source="source.com"
basedir="/home/xyz/"
search="*/*/*/*.zip"
register=received_files.txt
tempfile="/home/sai/dir_listing.txt"
gets=get_commands.txt
username="abc"
password="cvf"
 
ftp $source >> $tempfile <<-EOF
user $username
$password
cd $basedir
dir $search
quit
EOF