Hi I'm trying to make a extended Image ZClass. The basic idee is that I would like to have some more properties, like copyright, description ... Unfortunately when I try to add such a object I get always the following error: Error Type: Type Error Error Value: unsliceable object What is it what I'm doing wrong? I looked for hours through image products which are published on www.zope.org. I also studied How To's, tutorials, The Zope Book and Zope Developer Guide. But I couldn't find any info to help ... I got the same error when I tryed the How-To: ZClass Properties http://www.zope.org/Members/1staffor/zProperties . And this how to was very detailed and you can't do it wrong ... - so I really don't understand what it is what I'm doing wrong :( Is there someone around who can tell me what I'm doing wrong? Please answer .. I'm frustrated, desperate ... This are the definitions of my ZClass (OFS:Image) *Property Sheet: MainProperties *Properties: title(string), description(text), copyright(string) *ImgClass_addForm <HTML> <HEAD><TITLE>Add Extended Image</TITLE></HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#000099" VLINK="#555555"> <H2>Add Extended Image</H2> <form action="ImgClass_add" method="post" enctype="multipart/form-data"> <table> <tr> <th>Id</th> <td><input type=text name=id></td> </tr> <tr> <th>Title</th> <td><input type=text name=title></td> </tr> <tr> <th valign="Top">Description</th> <td><textarea name="description" rows="6" cols="35"></textarea></td> </tr> <tr> <th>Copyright</th> <td><input type=text name=copyright></td> </tr> <tr> <td align="left" valign="top"> File </td> <td align="left" valign="top"> <input type="file" name="file" size="25" value=""> </td> </tr> <tr> <td></td> <td><input type=submit value=" Add "></td> </tr> </table></form> </body></html> *ImgClass_add <HTML> <HEAD><TITLE>Add ImgClass</TITLE></HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#000099" VLINK="#555555"> <dtml-with "ImgClass.createInObjectManager(REQUEST['id'], REQUEST)"> <dtml-call "propertysheets.MainProperties.manage_editProperties(REQUEST)"> </dtml-with> <dtml-if NoRedir> <dtml-else> <dtml-if DestinationURL> <dtml-call "RESPONSE.redirect(DestinationURL+'/manage_workspace')"> <dtml-else> <dtml-call "RESPONSE.redirect(URL2+'/manage_workspace')"> </dtml-if> </dtml-if> </body></html> Best regards Stefan