Comment 2 for bug 128693

This bug has been encountered when running Ubiquity with the automatic-ubiquity kernel option in 16.04. The output of systemctl status ubiquity.service has the following:

systemd[1]: Starting Ubuntu live CD installer...
start-ubiquity-dm[XXXX]: debconf: DbDriver "templatedb": /var/cache/debconf/templates.dat is locaked by another process: Resource temporarily unavailable
...
start-ubiquity-dm[XXXX]: debconf: DbDriver "config": /var/cache/debconf/config.dat is locaked by another process: Resource temporarily unavailable
start-ubiquity-dm[XXXX]: Debconf database is locked!
start-ubiquity-dm[XXXX]: This may be because a package management program is running.
systemd[1]: ubiquity.service: Main process exited, code=exited, status=1/FAILURE
systemd[1]: Failed to start Ubuntu live CD installer.
systemd[1]: ubiquity.service: Unit entered failed state.
systemd[1]: ubiquity.service: Failed with result 'exit-code'.

Modifying /usr/share/ubiquity/start-ubiquity-dm to wait for the locks to be released seems to work around the issue.