So I just upgraded myself from 10.1 32-bit and 3 issues appeared.
1) lots of checksum warnings during the pre-installation section. Appears some checksums are missing. I'd say about 30 or so. No biggie now.
2) Grub installer errors. I've seen this before on previous releases. It can easily get confused.
3) System did boot. Grub bootloader is not executing. This isn't good. I'm in rescue mode I did a chroot on the mounted root partition with /boot also mounted and proc and when I try a "grub-install /dev/sda" and get:
 
/dev/sda does not have any corresponding BIOS drive
 
So I google and try "grub-install --recheck /dev/sda" and get:
 
Probing device to guess BIOS drives. this may take a long time.
Could not find device for /boot: Not found or not a block device.
 
 
??