The code below causes the tree tag to throws the following exception when a subitem is expanded. Traceback (innermost last): File /Zope/lib/python/ZPublisher/Publish.py, line 214, in publish_module File /Zope/lib/python/ZPublisher/Publish.py, line 179, in publish File /Zope/lib/python/Zope/__init__.py, line 202, in zpublisher_exception_hook (Object: CatalogAware) File /Zope/lib/python/ZPublisher/Publish.py, line 165, in publish File /Zope/lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: left) File /Zope/lib/python/ZPublisher/Publish.py, line 102, in call_object (Object: left) File /Zope/lib/python/OFS/DTMLMethod.py, line 145, in __call__ (Object: left) File /Zope/lib/python/DocumentTemplate/DT_String.py, line 502, in __call__ (Object: left) File /Zope/lib/python/DocumentTemplate/DT_In.py, line 691, in renderwob (Object: submissions) File /Zope/lib/python/TreeDisplay/TreeTag.py, line 154, in render (Object: a tree tag) File /Zope/lib/python/TreeDisplay/TreeTag.py, line 226, in tpRender (Object: CatalogAware) File /Zope/lib/python/TreeDisplay/TreeTag.py, line 543, in apply_diff (Info: ([None, (['AAAAAAAOXaM=', []],)], ['AAAAAAAObfc='])) AttributeError: (see above) If I reload the page however, it shows up fine with the item expanded. When I collapse, it throws the exception again. If I reload, the collapsed tree renders as it should. Sounds like a bug. Here's the code: <dtml-in tokens> <dtml-call "REQUEST.set('token',_[_['sequence-item']])"> <dtml-tree expr="token" branches_expr="objectValues(['Folder', 'DTML Method', 'DTML Document'])"> <a href="<dtml-var tree-item-url>" target="_parent"> <img src="<dtml-var icon>" border="0"><font size="-1"> <dtml-var title_or_id></font></a> </dtml-tree> <br> </dtml-in> The tokens property contains a list of id's of a few objects that are one folder above the document that contains the tree tag. Can anyone duplicate/explain this behavior? All my best, -- Jason Spisak webmaster@hiretechs.com