re-install after update system stalled/crash + encription stuck

Try to install 16.04 after system scrashed or stalled after update on 16.04.

Afterr several attempts the system didn't boot anymore.
The complication was the encripted disc, of which i have the key, but nowhere to enter this.
Do not know details- no access.

Boot using DVD, allowed encripted disc unliocked and formatted.
Try to install again but... someting crashed.
Some LVM volumes are already there.

I'm not a new user of Ubuntu linux, though not into the details, of UEFI, LVM, ..

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubiquity 2.21.63.3
ProcVersionSignature: Ubuntu 4.8.0-36.36~16.04.1-generic 4.8.11
Uname: Linux 4.8.0-36-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
CasperVersion: 1.376.2
Date: Sun Jul 23 16:22:22 2017
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --- maybe-ubiquity
LiveMediaBuild: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)