I have been trying to make a 32gb Sardu usb pen drive, every time I create the drive it won't boot with the error below. everything copies ok but it won't boot

thanks
SYSLINUX 4.06 EDD 2012-18-23 Copyright (C) 1994-12012 H. Peter Anvin et al
No DEFAULT or UI configuration Directive found!
boot: menu
Initial menu has no LABLE entries!
boot: _ <<<<<< there's a flashing cursor there