Python addin error: SystemError: NULL object passed to Py_BuildValue

Discussion created by ionarawilson on Oct 29, 2013
Latest reply on Oct 29, 2013 by ionarawilson
I have a python addin combox. Based on the selection of the combobox the user will get a message. When I test it inside Arcmap, I can see an error in the python window. Can anybody tell me what's wrong with my code that is producing this error? Thanks

This is the error:

SystemError: NULL object passed to Py_BuildValue

import arcpy
import pythonaddins

class ComboBoxClass1(object):
    """Implementation for SARS6_addin.combobox (ComboBox)"""
    def __init__(self):
        self.items = ["Forestry Stewardship", "Forestry Management Plan", "Reforestation Accomplished - TFS", "Reforestation Accomplished - Non TFS", "Tree Farm Program - Reinspections", "Tree Farm Program - New Inspections", "Certified Forest Steward - Assist", "Timber Theft Damage Appraisal", "Referral - Consulting Forester", "Referral Vendor", "Incidental Rural Forestry", "Prevention and Reduction of Pest Losses", "Forest Health Monitoring - Survey", "Forest Inventory & Analysis (FIA) Assist", "Best Management Practices (BMP) Assist"]
        self.editable = False
        self.enabled = True
        self.dropdownWidth = 'WWWWWWWWWWWWWWWWWWWWWWWWWWWWW'
    def onSelChange(self, selection):
         if selection == "Forestry Stewardship":
                    pythonaddins.MessageBox("If in edit mode, please digitize the stewardship boundary and run the ""Stewardship"" tool", "Warning", 0)
    def onEditChange(self, text):
    def onFocus(self, focused):
    def onEnter(self):
    def refresh(self):