Comment 141 for bug 1289977

@Saurabh, you seem to have a second copy of grub in the windows efi directory, and you are booting using the windows boot loader, which then chain loads this copy of grub when you select it from the menu. It is this second copy that is broken after upgrade since Ubuntu knows nothing about it. The question is, how did you come by this configuration? Did you install Windows after Ubuntu? Did you ever use grub-customizer?