You try to install Ubuntu in UEFI mode, but you do not have an EFI System Partition. I see some NTFS partitions, so if you have a Windows installed on the disk, you should boot the installer in the BIOS legacy mode t get a working dualboot.
** Changed in: grub-installer (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1762943 Title: grub fails to install in target partition, installer bail out. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1762943/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs