Crash during installtion of Ubuntu Studio 18.10LTS

[MORELLI]

Crash jusr after choosing the way to install (replace an exist system).

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: ubiquity 18.10.12
ProcVersionSignature: Ubuntu 4.18.0-10.11-lowlatency 4.18.12
Uname: Linux 4.18.0-10-lowlatency x86_64
ApportVersion: 2.20.10-0ubuntu13
Architecture: amd64
CasperVersion: 1.399
Date: Thu Feb 7 14:14:26 2019
InstallCmdLine: file=/cdrom/preseed/ubuntustudio.seed boot=casper only-ubiquity initrd=/casper/initrd quiet splash --- debian-installer/language=fr keyboard-configuration/layoutcode?=fr keyboard-configuration/variantcode?=oss
LiveMediaBuild: Ubuntu-Studio 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.2)
ProcEnviron:
 LANGUAGE=fr_FR.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)