I am in the middle of installing Z16.2 Core over Z15.3 Core.
On boot I get
error: symbol 'grub_file_filters' not found.
'>grub rescue
Have I missed something when setting up installation. I used Something Else method I've used in the past.
Maybe this should be a new thread.
I bit the bullet and decided to install 16.2 Core instead of using the Upgrader. But have come unstuck as the ubiquity installer is a bit different from Z12 and Z15. Have I missed step re bootloader. I could not see that during installation dialogue.
From LIve USB Gparted.
/dev/sda1 is ntfs (i.e. Windows)
/dev/sda2 is extended and includes
sda5 linux-swap
sda6 ext4 which should be / (root)
sda7 ext4 which should be /home
I had the same problem so I will leave this here How to Use Grub Rescue to Fix Linux Boot Failure | phoenixNAP KB . that is actually what helped me restore my grub boot because some odd reason it saved my grub loader to my hdd rather than ssd and got it moved eventually.