install android prebuilt images on EMMC of Black beagle bone board

I want to install android prebuilt images on EMMC of Black beagle bone board(4GB type)

so I followed the instruction in this site:
http://www.2net.co.uk/tutorial/android-4.4-beaglebone-update#comment-5720

every thing ok until step 7 on that tutorial but when I execute this command:

`

$ fastboot flash spl MLO

it show me this error:
ERROR: CAN NOT LOAD MLO

please guide me how can I fix this problem ?

`