Lightdm no longer works after 18.04 upgrade

[Kevin Dalley]

Both lightdm and gdm3 no longer work after the 18.04 upgrade, though I have been able to use lxdm, somewhat, if I use LXDE.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: lightdm 1.26.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: LXDE
Date: Mon May 14 17:06:53 2018
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-05-18 (1092 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.pam.d.lightdm: 2018-05-10T11:40:28.736754
mtime.conffile..etc.pam.d.lightdm-greeter: 2018-05-10T11:40:45.424698

[Kevin Dalley (nereocystis)]

I commented out pam_kwallet.so in /etc/pam.d/
lightdm and lightdm-greeter

since this shared library does not exist, and I received warning messages about it.