Comment 10 for bug 1716982

FWIW, i was using dash-to-dock with ubuntu-dock still installed
after today's update, the dash (ie not the modified dock) was visible from lock screen and I was able to interact with it (ie clicked on icons and when unlocked found associated programs open).

workaround:
apt-get purge gnome-shell-extension-ubuntu-dock
apt-get autoremove (not required but I like to just in case)
reboot

all back to normal