Sorry, i missed comment #29, but there are a lot of bug reports out there, some of them over a year old, which describe the same issue.
My reproduction steps, tested on a virtualbox machine: 1) Fresh-Install Ubuntu 18.0.4.1 LTS 2) Install package 'chrome-gnome-shell' 3) Navigate to https://extensions.gnome.org/extension/307/dash-to-dock, install firefox/chrome extension and install dash-to-dock extension. 4) Restart 5) On next lock the ubuntu-dock reappears and the following journalctl /usr/bin/gnome-shell output is generated: Nov 15 12:53:15 ubuntu gnome-shell[1143]: Extension "ubuntu- d...@ubuntu.com" had error: TypeError: dockManager is null The suggested fix is resolving this and a quick look into https://git.launchpad.net/ubuntu/+source/gnome-shell-extension-ubuntu-dock/tree/extension.js?h=ubuntu/bionic exposes, that the issue is a simple missing null-check in the disable() function where dockManager.destroy() is called on a null-instance, which should be added in either way. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell-extension-ubuntu-dock in Ubuntu. https://bugs.launchpad.net/bugs/1769383 Title: Ubuntu dock/launcher is shown on the lock screen Status in gnome-shell package in Ubuntu: Incomplete Status in gnome-shell-extension-ubuntu-dock package in Ubuntu: In Progress Status in gnome-shell source package in Cosmic: Incomplete Status in gnome-shell-extension-ubuntu-dock source package in Cosmic: In Progress Status in gnome-shell source package in Disco: Incomplete Status in gnome-shell-extension-ubuntu-dock source package in Disco: In Progress Bug description: After an update from ubuntu 16.04 to 18.04 the dock is aviable on the lockscreen after user login. I did not configure this knowingly. Also i can start every application which is available on the dock. Settings, virtual box, visualstudio code and so on. After the update to 18.04 i just configure the screen frequency to 144Hz and the night mode on. And attach the dock on bottom. I later undid these customizations back to configuration before, but the dock is stil aviable on lockscreen. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: gnome-settings-daemon 3.28.1-0ubuntu1 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Sat May 5 18:30:16 2018 InstallationDate: Installed on 2018-04-08 (27 days ago) InstallationMedia: Ubuntu 16.04.4 LTS "Xenial Xerus" - Release amd64 (20180228) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash SourcePackage: gnome-settings-daemon UpgradeStatus: Upgraded to bionic on 2018-05-01 (3 days ago) --- ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 CurrentDesktop: ubuntu:GNOME DistroRelease: Ubuntu 18.04 InstallationDate: Installed on 2018-04-08 (27 days ago) InstallationMedia: Ubuntu 16.04.4 LTS "Xenial Xerus" - Release amd64 (20180228) NonfreeKernelModules: nvidia_modeset nvidia Package: gnome-shell-extension-ubuntu-dock 0.9.1 PackageArchitecture: all ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Tags: bionic Uname: Linux 4.15.0-20-generic x86_64 UpgradeStatus: Upgraded to bionic on 2018-05-01 (4 days ago) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1769383/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
