Changing Bootloaders topic

The CM12 release seems to kickback an error if the bootloader and recovery aren't properly aligned. But I haven't been able to find a way to specifically change the bootloader, I suspect its going on behind the scenes. I've got custom recovery (TWRP, and i have tried several versions) and have flashed a wide variety of ROMs. I also just "rerooted" my device with effortless stuff because I was getting signal issues. Even in this rerooting process I didn't seem to directly change the bootloader.

What bootloader/recovery combo can i flash to get CM12 working?