xubuntu 18.04.1 locking to black screen 4.19.2

[xanadu1977]

Xubuntu 18.04.1 using kernel 4.19.2 locking screen with crtl-alt-del locks to unrecoverable black screen 100% of the time. Kernels 4.19.1 and 4.19 both lock fine. This is only with kernel 4.19.2. All kernels were installed using ukuu 18.9 and machine is up to date as of 14Nov2018.

light-locker:
  Installed: 1.8.0-1ubuntu1
  Candidate: 1.8.0-1ubuntu1
  Version table:
 *** 1.8.0-1ubuntu1 500
        500 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        100 /var/lib/dpkg/status

Description: Ubuntu 18.04.1 LTS
Release: 18.04

Linux Alienware-17-R4 4.19.2-041902-generic #201811132032 SMP Tue Nov 13 20:34:19 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: light-locker 1.8.0-1ubuntu1
Uname: Linux 4.19.2-041902-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CurrentDesktop: XFCE
Date: Wed Nov 14 11:09:15 2018
InstallationDate: Installed on 2018-10-24 (21 days ago)
InstallationMedia: Xubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
SourcePackage: light-locker
UpgradeStatus: No upgrade log present (probably fresh install)

[Theo Linkspfeifer (lastonestanding)]

Why is this a bug in light-locker then? Does terminating light-locker and running "dm-tool lock" produce the same result?

[xanadu1977 (jason-kaiser)]

I hate to say but I got super frustrated and trashed light-locker and installed gnome-screensaver. All is well now.

[Theo Linkspfeifer (lastonestanding)]

Closing this report then.

[Stéphane Guillou (stephane-guillou)]

Having a similar issue with Ubuntu Studio 18.04, I found this solution: https://xubuntu.org/news/laptop-users-fix-available-for-the-black-screen-on-unlock-bug/

Possibly the same thing?

In my case, I even had to first install Light Locker Settings, to then be able to turn it on and off.

I thought this might be useful for people landing here when searching for this issue.