Ubiquity error Xubuntu 18.04

[BaaTLT]

Crash Ubiquity when localizing a new installed system.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14.6 [modified: usr/share/ubiquity/apt-setup]
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CasperVersion: 1.394
Date: Thu Sep 13 00:27:52 2018
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/custom.seed boot=casper initrd=/casper/initrd.gz quiet splash --
LiveMediaBuild: Custom 18.04 - Release amd64
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[BaaTLT (baa-tlt)]

Syslog attachment.

[Paul White (paulw2u)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to review all reported bugs in a timely manner.

This release of Ubuntu is no longer receiving maintenance updates:
https://xubuntu.org/news/xubuntu-18-04-release/

If this is still an issue when using a currently supported release of Xubuntu then please let us know.