Your disk is formatted using GPT but your computer is booting in bios mode. You will have to create a 1 mb bios_grub partition to install grub.
** 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/1424209 Title: fail to install ubuntu in UEFI mode (unable to install grub) ubuntu 15.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1424209/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs