--- a/editors/Viewer.py	Thu Oct 04 11:25:42 2018 +0300
+++ b/editors/Viewer.py	Thu Oct 04 12:07:16 2018 +0300
@@ -30,6 +30,7 @@
 from threading import Lock
 
 import wx
+from six.moves import xrange
 
 from plcopen.structures import *
 from plcopen.types_enums import ComputePouName