package lightdm 1.18.2-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Fabio Monteverde]

find a solution please!

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: lightdm 1.18.2-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-31.50-generic 4.4.13
Uname: Linux 4.4.0-31-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
Date: Sat Jul 16 10:54:48 2016
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2016-05-13 (63 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 1.18.2-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)