Traceback (most recent call last):
  File "/usr/lib/ubiquity/ubiquity/frontend/gtk_ui.py", line 1441, in on_next_clicked
    self.dbfilter.ok_handler()
  File "/usr/lib/ubiquity/plugins/ubi-partman.py", line 3149, in ok_handler
    self.ui.get_autopartition_choice()
  File "/usr/lib/ubiquity/plugins/ubi-partman.py", line 696, in get_autopartition_choice
    disk = m.get_value(i, 0)
  File "/usr/lib/python3/dist-packages/gi/types.py", line 113, in function
    return info.invoke(*args, **kwargs)
TypeError: Argument 1 does not allow None as a value