Trouble flashing Cm 11 nightly topic

Hi, everyone. I'm having some trouble trying to flash thE Cm 11 20140217 d2att nightly rom. I'm currently running Cm 10.2 nightly and when I go to flash the cm11 zip, I am getting a ro.buildprop bootloader i747 error which causes the installation to abort. I'm stumped. Any help is much appreciated. Thanks!