--- a/controls/FolderTree.py	Fri Nov 23 11:01:20 2018 +0100
+++ b/controls/FolderTree.py	Fri Nov 23 12:13:24 2018 +0100
@@ -27,6 +27,7 @@
 import os
 
 import wx
+from six.moves import xrange
 
 from util.BitmapLibrary import GetBitmap