Can you please run “apport-collect 1802094” on the affected machine? This command will attach some logs to this bug.
Also can you try GDM instead of LightDM? Use “sudo dpkg-reconfigure gdm3” to select the default display manager. Or maybe even log in directly, without any DM, by entering these commands in a tty: # systemctl stop lightdm.service # update-alternatives --set x-session-manager /usr/lib/gnome-flashback/gnome-flashback-metacity # startx Then check whether it works and what it prints, and use this command to undo update-alternatives changes: # update-alternatives --auto /usr/lib/gnome-flashback/gnome-flashback- metacity -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1802094 Title: Can not start Flashback session in 18.04 (Bionic) after update from 16.04 (Xenial) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-flashback/+bug/1802094/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs