Traceback (most recent call last):
  File "/usr/lib/ubiquity/ubiquity/frontend/gtk_ui.py", line 1383, in watch_debconf_fd_helper
    return callback(source, debconf_condition)
  File "/usr/lib/ubiquity/ubiquity/filteredcommand.py", line 252, in process_input
    self.status = self.wait()
  File "/usr/lib/ubiquity/ubiquity/filteredcommand.py", line 148, in wait
    self.cleanup()
  File "/usr/lib/ubiquity/plugins/ubi-language.py", line 740, in cleanup
    i18n.reset_locale(self.frontend)
  File "/usr/lib/ubiquity/ubiquity/i18n.py", line 45, in reset_locale
    di_locale = frontend.db.get('debian-installer/locale')
AttributeError: 'NoneType' object has no attribute 'get'