[Q] can't install KK from recovery mode topic

i tried to go to recovery mode to install CM 11 which is KitKat of course but it keeps on failing..I can install any kind of rom that's jelly bean but when i try to install a kitkat rom, it won't let me. right now, i am using the latest CarbonRom Nightly and i'm trying to transition to CM 11. i did the factory reset, clear cache, and clear dalvik cache but it still won't work. what should i do? any help would be great! Thanks!