I also tried exporting one of the broken ZClass products from a 2.5 Zope and importing it into 2.6. I get the following traceback: For the URL http://devhost1:8180/Control_Panel/Products/manage_importObject No error message. Error type: ImportError Error value: No module named iclass <p>Traceback (innermost last): <ul> <li> Module ZPublisher.Publish, line 98, in publish</li> <li> Module ZPublisher.mapply, line 88, in mapply</li> <li> Module ZPublisher.Publish, line 39, in call_object</li> <li> Module OFS.ObjectManager, line 535, in manage_importObject</li> <li> Module OFS.ObjectManager, line 551, in _importObjectFromFile</li> <li> Module ZODB.ExportImport, line 79, in importFile</li> <li> Module ZODB.Transaction, line 236, in commit</li> <li> Module ZODB.Transaction, line 351, in _commit_objects</li> <li> Module ZODB.Connection, line 302, in commit</li> <li> Module ZODB.ExportImport, line 147, in _importDuringCommit</li> </ul>ImportError: No module named iclass </p> Looking in an XML export of one of the broken products, the offending line is <global id="1067586.19" name="Interface" module="Interface.iclass"/> There's a lib/python/Interface/iclass.py in 2.5, but it's missing in my 2.6 checkout... Is some module aliasing needed here? I added a simple lib/python/Interface/iclass.py that just contained from _Interface import Interface, but attempts to import now fail with No error message. Error type: UnpicklingError Error value: <Interface Interface._Interface.Interface at 53cc18> is not safe for unpickling So that's not a simple workaround. Dammit. (I can make a copy of one of the broken ZClass-based products available if someone wants to have a look at making this work... let me know...) Anthony