Follow that howto, and remember to use not only 'primary' partitions as seen into the ubiquity output: 'primary' cant be more than 4, so set an 'extended' partition and max 3 'primary ones.
https://www.tecmint.com/install-ubuntu-16-04-alongside-with- windows-10-or-8-in-dual-boot/ As you have not followed the basic partitionning rules, that report is a false positive, and so been closed. ** 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/1744446 Title: when installing alongside Wondows 10 from live USB stick the grub loader could not install To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1744446/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs