Verify the md5sum that you have good media. You should be able to boot the ISO image itelf over iLO (if you have the advanced license) or you can create a bootable DVD from teh ISO. I've used this iamge numerous times on many different Gen8 server models to update to the latest version
http://h20566.www2.hpe.com/hpsc/swd/public/detail?swItemId=MTX_c02fd94d9eba4d52a2cc30b34e