Comment 2 for bug 1830066

You have the grub package installed on your system, which is grub 1.x and is not the default bootloader in Ubuntu 14.04; and you have not configured the package, which means it causes kernel installation to fail at the bootloader stage.

The solution is for you to remove the grub package from your system with 'sudo apt-get remove --purge grub' as this package is not needed. You should be using the default grub-pc package instead.