Cannot unlock screen after locking it manually in Xubuntu

[bmaupin]

If I lock my screen manually using Ctrl-Alt-Del, when I try to unlock it, it appears that my monitor is in power save mode. In addition, my keyboard doesn't respond at all. The only way I can unlock the computer is by powering it off.

I believe this is related to this bug:

https://bugs.launchpad.net/ubuntu/+source/xubuntu-default-settings/+bug/1303736

Because this fixed my problem:

https://bugs.launchpad.net/ubuntu/+source/xubuntu-default-settings/+bug/1303736/comments/140

But it came back, so apparently the bug hasn't been completely fixed. Following the steps above fixed it again, but I'm not convinced the problem is fixed.

In addition, that referenced bug is 1. only for laptops (I'm using a desktop) and 2. I'm not suspending my computer, just locking the screen. So either this is an entirely different bug altogether or the referenced bug needs to be updated to reflect that it isn't limited to laptops and suspending.

In the meantime, I can't risk this coming up again so I'm uninstalling light-locker:

https://bugs.launchpad.net/ubuntu/+source/xubuntu-default-settings/+bug/1303736/comments/53

Another possible related bug:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1357090

More information:

$ dmesg | grep DMI
[ 0.000000] DMI: Dell Inc. OptiPlex 9020/0PC5F7, BIOS A05 12/05/2013

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04.1 LTS
Release: 14.04
Codename: trusty

$ uname -rvp
3.13.0-37-generic #64-Ubuntu SMP Mon Sep 22 21:28:38 UTC 2014 x86_64

$ dpkg -l light-locker-settings xfce4-power-manager xfce4-power-manager-data xubuntu-default-settings
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============================================-============================-============================-==================================================================================================
ii light-locker-settings 1.2.1-0ubuntu1.1 all simple configuration tool for light-locker
ii xfce4-power-manager 1.2.0-3ubuntu4.1 amd64 power manager for Xfce desktop
ii xfce4-power-manager-data 1.2.0-3ubuntu4.1 all power manager for Xfce desktop, arch-indep files
ii xubuntu-default-settings 14.04.5 all default settings for the Xubuntu desktop

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: light-locker-settings 1.2.1-0ubuntu1.1
ProcVersionSignature: Ubuntu 3.13.0-37.64-generic 3.13.11.7
Uname: Linux 3.13.0-37-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.14.1-0ubuntu3.5
Architecture: amd64
CurrentDesktop: XFCE
Date: Tue Nov 4 10:23:21 2014
InstallationDate: Installed on 2014-08-25 (70 days ago)
InstallationMedia: Xubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140723)
PackageArchitecture: all
SourcePackage: light-locker-settings
UpgradeStatus: No upgrade log present (probably fresh install)

[Theo Linkspfeifer (lastonestanding)]

Closing this old report.

Please let us know if the problem still affects newer Xubuntu releases.

[bmaupin (bmaupin)]

I don't recall having this issue with 16.04 or 18.04. Thanks!