"Object has no Attribute"the second time through arcpy script

Discussion created by bentleyemail on Jan 24, 2012
Latest reply on Dec 3, 2013 by sofoo
I created a toolbox that contains a few tools from the Arc Hydro Groundwater Tool Suite that I like to use in my modeling.  The tools import alright and I can run the script once, but when I try to run the same script a second time with the same inputs I get a message saying the following:

"<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute"

If I close Arc Map and run the script again, the script will run one time. If a try to run it twice I get the same error message as above.  This cycle has proven itself to repeat indefinitely.  What could be causing this, do I need to clear something out at the end of the toolbox import?

import arcpy
arcpy.ImportToolbox("D:\GIS_Geodatabase\ES12.mdb\mytools", "mytools")