package lightdm 1.18.1-0ubuntu1 failed to install/upgrade: subprocess installed pre-removal script returned error exit status 10

[Anthony]

removed and reinstalled due to graphical error with Radeon video card.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: lightdm 1.18.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-22.40-generic 4.4.8
Uname: Linux 4.4.0-22-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
AptOrdering:
 ubuntu-desktop: Purge
 lightdm: Purge
 NULL: ConfigurePending
Architecture: amd64
Date: Wed Jun 8 20:50:25 2016
DpkgTerminalLog:
 Removing ubuntu-desktop (1.361) ...
 Removing lightdm (1.18.1-0ubuntu1) ...
 dpkg: error processing package lightdm (--purge):
  subprocess installed pre-removal script returned error exit status 10
DuplicateSignature:
 package:lightdm:1.18.1-0ubuntu1
 Removing lightdm (1.18.1-0ubuntu1) ...
 dpkg: error processing package lightdm (--purge):
  subprocess installed pre-removal script returned error exit status 10
ErrorMessage: subprocess installed pre-removal script returned error exit status 10
InstallationDate: Installed on 2016-05-31 (8 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.12~ubuntu16.04.1
SourcePackage: lightdm
Title: package lightdm 1.18.1-0ubuntu1 failed to install/upgrade: subprocess installed pre-removal script returned error exit status 10
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.