When I include the following line of code: from Persistence.PersistentMapping import PersistentMapping in my Product, it causes this error when I try to import it: AttributeError: 'Persistence.PersistentMapping' module has no attribute '__basicnew__' after which I have to restart Zope from the command line, the error continues to be displayed with every request, so I can not use the management interface. This line of code, however, works fine: from Persistence.PersistentList import PersistentList Is this a bug in Zope? I can't imagine why PersistentList would work fine, but PersistentMapping will not even import. The source code is there for both, and I have tried reinstalling Zope in case it was a corrupt file or something, but no luck. I can of course just create my own object with a normal {}, and use _p_changed=1 as needed, but I wanted to share and see if anyone else had experienced this problem. Zope Version (Zope 2.6.2 (binary release, python 2.1, win32-x86), python 2.1.3, win32) Python Version 2.1.3 (#35, Apr 8 2002, 17:47:50) [MSC 32 bit (Intel)] --Sean Complete Error Message: Site Error An error was encountered while publishing this resource. exceptions.AttributeError Sorry, a site error occurred. Traceback (innermost last): Module ZPublisher.Publish, line 150, in publish_module Module ZPublisher.Publish, line 114, in publish Module Zope.App.startup, line 174, in zpublisher_exception_hook Module ZODB.ZApplication, line 61, in __bobo_traverse__ Module ZODB.Connection, line 532, in root Module ZODB.Connection, line 160, in __getitem__ __traceback_info__: ('\x00\x00\x00\x00\x00\x00\x00\x00', '((U\x0bPersistenceq\x01U\x11PersistentMappingq\x02tq\x03Nt.}q\x04U\n_contai nerq\x05}q\x06(U\n_pack_timeq\x07GA\xcb\x97\x14bV\xc2\x9cU\x0bRefreshDataq\x 08(U\x08\x00\x00\x00\x00\x00\x02jPq\t(h\x01U\x11PersistentMappingq\nttQU\x08 ZGlobalsq\x0b(U\x08\x00\x00\x00\x00\x00\x00\x00[q\x0c(U\x05BTreeq\rU\x05BTre eq\x0ettQU\x0bApplicationq\x0f(U\x08\x00\x00\x00\x00\x00\x00\x00\x02q\x10(U\ x0fOFS.Applicationq\x11U\x0bApplicationq\x12ttQus.') AttributeError: 'Persistence.PersistentMapping' module has no attribute '__basicnew__'