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 …

in Plone · Wed 14 September 2011

Plone 4: Local Zeo blobs conflict with Plone instance

As the title suggests, there’s a conflict between a Zeo database instance being run together with a Plone 4/Zope instance, and them trying to share the same blob storage folder.  But, this only happens if you misunderstand or incorrectly set the option of  shared-blob = off, and blob-storage to be the same location as for Zeo in your buildout. If that previous set of (seemingly jumbled) thoughts doesn’t make any sense to you, then move along, nothing to see here.

By default, at the time of writing, blob support within Zeo runs with the bushylayout, and creates …

in Plone · Tue 06 July 2010

Ubuntu 9.10 install hiccough

Yay, the new version of Ubuntu is out.  With it comes plenty of cool new features (how awesome does the start up and login screen look now?) and also plenty of opportunities for things to break when I’ve become so accustomed to having them working.  At least it’s not Windows though — I think I may just gnaw my own limbs off before I have to get forced to upgrade to Windows 7 for gaming reasons.

But I digress, there was one reasonably small problem with the upgrade that I saw on both of my Ubuntu machines (laptop and …

in IT, Linux · Fri 30 October 2009