Last time there was a new Zope version, Anthony Baxter wrote: """Ok, has anyone thought about putting together an upgrade guide for upgrading Zope versions? Steps I'm undertaking: . install new version install ZServer into new version (hm, do I still need to update Folder.py?) . copying external methods and products from old to new installations . transferring bobobase. either by exporting the old one, and importing the new, or by just copying over the Data.bbb. The former is more of a pain, the latter means you lose any new stuff in the default bobobase. """ I tried copying my 1.10.2 var directory to the 1.11 installation and things broke. I also tried exporting the object (folder). Looking in the management screen, everything seems OK. When I tried to use my application I got: <!-- Traceback (innermost last): File /opt/zope/Zope-1.11.0pr1-src/lib/python/ZPublisher/Publish.py, line 255, in publish_module File /opt/zope/Zope-1.11.0pr1-src/lib/python/ZPublisher/Publish.py, line 165, in publish File /opt/zope/Zope-1.11.0pr1-src/lib/python/BoboPOS/TJar.py, line 281, in commit File /opt/zope/Zope-1.11.0pr1-src/lib/python/BoboPOS/TJar.py, line 200, in maybe_commit_objects AttributeError: _p_changed --> So, what is the "true path to upgrading"? I looked in the ZDP's FAQ an all I found was a quote from DC saying that applications may be retained after upgrade. Richard