Error when trying to open Preferences

[Unichronic]

There is a error when trying to open preferences. To reproduce click on the settings icon on the task bar or Go to Option > Preferences.

Traceback (most recent call last):
  File "C:\Users\user\invesalius3\invesalius\gui\frame.py", line 584, in OnMenuClick
    self.ShowPreferences()
  File "C:\Users\user\invesalius3\invesalius\gui\frame.py", line 745, in ShowPreferences
    preferences_dialog = preferences.Preferences(self, page)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\user\invesalius3\invesalius\gui\preferences.py", line 42, in __init__
    self.visualization_tab = VisualizationTab(self.book)
                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\user\invesalius3\invesalius\gui\preferences.py", line 166, in __init__
    self.conf = dict(self.session.GetConfig("mep_configuration"))
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not iterable