I hunted out this as I had a similar problem as I was installing without CD-ROM by extracting the ISO to an existing Fedora install and booting from there via grub.
I *simply* performed the following which prompted ubiquity to spring back to the realm of usable: sudo umount -l -r -f /dev/sda3 (where sda3 was the device mounted as cdrom) -- no partitions listed in partition table https://bugs.launchpad.net/bugs/288675 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs