fix

src/settings/setting/setting.py

@@ -53,6 +53,7 @@ class Setting:
         if isinstance(self.map, list) and 'choice' in self.type:
             self.map = {
                 item.title(): item for item in self.map
+                if item is not None
             }
 
 

src/settings/widgets/service_dialog.py

@@ -20,7 +20,7 @@ class ServiceNotStartedDialog(Adw.AlertDialog):
         self.add_response("yes", _("Yes"))
         self.add_response("no", _("No"))
 
-        self.connect('response', on_response)
+        self.connect('response', self.on_response)
 
     def on_response(self, dialog, response):
         if response == "yes":