Comment 0 for bug 1632473

The yakkety/arm64 Ubuntu Server ISO 20161008 daily build fails to boot. After selecting "Install Ubuntu Server" from the GRUB menu, the following message appears:

error: invalid magic number.
unaligned pointer 0xb84630e8
Aborted. Press any key to exit.

This is due to the arm64 kernel now being gzip'd (See LP: #1384955), and GRUB not having loaded the gzio module. Whatever generates the grub.cfg for the cdimages likely needs to be updated to load this module in advance of loading the kernel.

Workaround:
 - At the GRUB menu, press "c" to enter the GRUB shell
 - At the shell, run 'insmod gzio'
 - Press escape to return to the GRUB menu
 - Make your boot selection as per normal.