Erro winusb montando windows 10 em hd externo

Installation failed !
Exit code: 256
Log:
Formatting device...
Wait 3 seconds for block device nodes to populate...
mkfs.fat: warning - lowercase labels might not work properly with DOS or Windows
mkfs.fat 4.0 (2016-05-06)
Mounting...
Copying...
Installing grub...
Installing for i386-pc platform.
Instalação finalizada. Nenhum erro foi relatado.
Installing grub.cfg...
Exiting...
Syncing...
/usr/bin/winusb: linha 78: 1148 Terminado while true; do
sleep 0.05; echo 'pulse';
done
Cleaning...
/usr/bin/winusb: linha 78: 1294 Terminado while true; do
sleep 0.05; echo 'pulse';
done
Unmounting and removing '/media/winusb_iso_1478797225_29588'...
Unmounting and removing '/media/winusb_target_1478797225_29588'...