Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/electrum/gui/qt/wizard/wizard.py", line 213, in on_back_button_clicked
    self.update()
    ~~~~~~~~~~~^^
  File "/usr/lib/python3/dist-packages/electrum/gui/qt/wizard/wizard.py", line 188, in update
    self.setWindowTitle(page.wizard_title if page.wizard_title else self.window_title)
                                             ^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'wizard_title'