It appears that you partitioned your disk with GPT but your computer is bios based rather than UEFI. To install grub in such a setup requires that you have a 1 MB bios_grub boot partition on the disk.
** Changed in: grub-installer (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1360990 Title: While installing Ubuntu 14.04 LTS 64 bits I see an error that the GRUB is unable to install To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1360990/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs