The attached file contains the error message that occurred when I tried to add an object. The object itself is defined in a custom product. However, that ZClass itself was made with the standard tools in Zope 2-3-1 (an oldie, but a goodie). I caughed up when I was trying to create the object. The add DTML is below (unadultered after it was created by the wizard): <HTML> <HEAD><TITLE>Add sw_patent_property</TITLE></HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#000099" VLINK="#555555"> <dtml-comment> We add the new object by calling the class in a with tag. Not only does this get the thing added, it adds the new thing's attributes to the DTML name space, so we can call methods to initialize the object. </dtml-comment> <dtml-with "sw_patent_property.createInObjectManager(REQUEST['id'], REQUEST)"> <dtml-comment> You can add code that modifies the new instance here. For example, if you have a property sheet that you want to update from form values, you can call it here: <dtml-call "propertysheets.Basic.manage_editProperties( REQUEST)"> </dtml-comment> </dtml-with> <dtml-comment> Now we need to return something. We do this via a redirect so that the URL is correct. Unfortunately, the way we do this depends on whether we live in a product or in a class. If we live in a product, we need to use DestinationURL to decide where to go. If we live in a class, DestinationURL won't be available, so we use URL2. </dtml-comment> <dtml-if DestinationURL> <dtml-call "RESPONSE.redirect( DestinationURL+'/manage_workspace')"> <dtml-else> <dtml-call "RESPONSE.redirect( URL2+'/manage_workspace')"> </dtml-if> </body></html> Any idea what the problem could be? I'm surprised to get this error as the only thing that I did was create a ZClass and then try to instantiate an object. Thanks in advance for any hints or advice. Ron