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 Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1769383 Title: Ubuntu dock/launcher is shown on the lock screen To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1769383/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
