Nandroid backup failed exitcode[127]

I need to create a customized flashable ROM, by customized i mean i will add some apps into it and redistribute this new ROM. Now, first of all I've read that I could create a flashable ROM through Nandroid backups. but somehow when installed and execute a Clockwork backup it returns just this:

Starting backup...
Running with the following commands : -o --utc --storage /sdcard -pd -r
Using default shell
exitcode[127]

What's happening? Actually this is not a Smartphone but an Android Head Unit called Full AOSP on Mstar Cedric3 I can put zip file to upgrade the firmware instead the official readme suggest that i should extract all zip contents into a micro sd card and the device will update the contents one by one like first CIS, boot, recovery, system, data etc etc

any help?