Issue is really that to boot in UEFI mode you should have gpt. And most systems now have gpt as windows in UEFI mode requires gpt. But if installing in BIOS/Legacy/CSM boot mode to gpt drive, you must have a bios_grub partition which is only 1 or 2MB unformatted with bios_grub flag.
Or if installing in UEFI boot mode to gpt drive, you must have an ESP - efi system partition which is fat32 with boot flag. If you do not have correct partitions for boot mode, then grub install fails. Boot-Repair will tell you that you need the correct partition, and grub should at least explain why it is not installing, like Boot-Repair does. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1771651 Title: The installation fails with a "GRUB installation failed" message. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1771651/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
