AttributeError: ‘NoneType’ object has no attribute ‘items’: Can’t upgrade Plone 3 to 4.x
You may have seen an error like the one below when you’ve gone to upgrade your Plone site to something in the Plone 4.x series from Plone 3:
2011-09-14 08:43:32 ERROR plone.app.upgrade Upgrade aborted. Error: Traceback (most recent call last): File "/home/david/.buildout/eggs/Products.CMFPlone-4.1-py2.6.egg/Products/CMFPlone/MigrationTool.py", line 175, in upgrade step['step'].doStep(setup) File "/home/david/.buildout/eggs/Products.GenericSetup-1.6.3-py2.6.egg/Products/GenericSetup/upgrade.py", line 142, in doStep self.handler(tool) File "/home/david/.buildout/eggs/plone.app.upgrade-1.1-py2.6 …