Installer doesn't support an encrypted LVM install alongside Windows, so I do the encrypted LVM for it; it crashes when I click on the /dev/mapper/${LUKS_name}

[Dźwiedziu]

1)
Description: Ubuntu 17.10
Release: 17.10

2)
ubiquity:
  Installed: 17.10.10
  Candidate: 17.10.10
  Version table:
 *** 17.10.10 500
        500 http://archive.ubuntu.com/ubuntu artful/main amd64 Packages
        100 /var/lib/dpkg/status

3) Choose to install an encrypted volume for installation. I should be given a wrapper to cryptsetup luksFormat, then be able to configure an LVM, choose /boot from another manually made partition, choose / on the LVM, then install.

4) Choosing a partition to become an encrypted volume causes nothing to happen. Nor does clicking "Install". Trying to click a manually made LUKS volume in partman causes the installer to crash with this message:
Traceback (most recent call last):
  File "/usr/lib/ubiquity/ubiquity/frontend/kde_components/PartMan.py", line 416, in on_partition_list_treeview_activated
    self.ctrlr.dbfilter.create_label(devpart)
  File "/usr/lib/ubiquity/plugins/ubi-partman.py", line 3272, in create_label
    assert self.current_question == 'partman/choose_partition'
AssertionError

Also managed to make one install (forgotten the exact installation details, except it was also on a encrypted LVM), but it was not bootable, and went into initramfs shell. GRUB didn't have any crypto options supplied.

lsblk output:
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 1.6G 1 loop /rofs
sda 8:0 1 3.8G 0 disk /cdrom
├─sda1 8:1 1 1.7G 0 part
└─sda2 8:2 1 2.3M 0 part
nvme0n1 259:0 0 238.5G 0 disk
├─nvme0n1p1 259:7 0 550M 0 part
├─nvme0n1p2 259:8 0 128M 0 part
├─nvme0n1p3 259:9 0 49.4G 0 part
├─nvme0n1p4 259:10 0 811M 0 part
├─nvme0n1p5 259:11 0 2G 0 part
└─nvme0n1p6 259:12 0 185.7G 0 part
  └─ubuenc 253:0 0 185.7G 0 crypt
    └─vgubu-lvroot 253:1 0 185.7G 0 lvm

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: ubiquity 17.10.10
ProcVersionSignature: Ubuntu 4.13.0-21.24-generic 4.13.13
Uname: Linux 4.13.0-21-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.7
Architecture: amd64
CasperVersion: 1.387
CurrentDesktop: KDE
Date: Fri Jan 26 13:43:36 2018
LiveMediaBuild: Kubuntu 17.10 "Artful Aardvark" - Release amd64 (20180105.2)
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)