It's the KitKat update. You won't be able to install the actual update since you are rooted and running custom recovery. If you want to update you'll need to flash the complete stock tar file from this thread @.This will completely revert your phone to 100% stock but on the new KitKat update. You will have to reflash recovery and reroot. Keep in mind that this will also upgrade your bootloader to the newest Knox bootloader. Won't affect rooting or running custom roms but it does mean you can't flash back to an older stock firmware (ie. mk5) and rooting will trip the Knox flag which voids your warranty.