--- a/Preferences/ConfigurationDialog.py	Sun Mar 04 14:55:23 2018 +0100
+++ b/Preferences/ConfigurationDialog.py	Mon Apr 02 12:04:18 2018 +0200
@@ -855,7 +855,7 @@
         Public method called to store the selected values into the preferences
         storage.
         """
-        for key, pageData in list(self.configItems.items()):
+        for pageData in self.configItems.values():
             if pageData[-1]:
                 pageData[-1].save()
                 # page was loaded (and possibly modified)