Different with previous, latest 6.5.1.b using /home/lxadmin/mail/domains/<domain.com> owner for re-create qmail-assign where previous version using vpopmail database data for this purpose.
So, you can use previous script with modified '/script/fix-qmail-assign':
from:
#!/bin/sh
#source /script/directory
#lxphp.exe ../bin/fix/fix-qmail-assign.php $*
#exit
d="/home/lxadmin/mail/domains"
q="/var/qmail"
echo "Fix Qmail User Assign"
...
to:
#!/bin/sh
source /script/directory
lxphp.exe ../bin/fix/fix-qmail-assign.php $*
exit
d="/home/lxadmin/mail/domains"
q="/var/qmail"
echo "Fix Qmail User Assign"
...