BBB emmc img update kernel failed

hello,

I download the beagblebone emmc flsasher img (from: https://rcn-ee.com/rootfs/bb.org/testing/2014-11-11/console/BBB-eMMC-flasher-debian-7.7-console-armhf-2014-11-11-2gb.img.xz), when i want to update the kernel to 4.4.9, it was always failed, what i did is:

sudo apt-get install linux-img-4.4.9…
sudo reboot

but it can not reboot successfully…

thanks,

Victor