Hello, I plan to write a product derived from Folder which has some keywords as additional properties. Those keywords should be included as meta tags of the documents of this folder. I tried to understand the Zope Developers Guide and copied the basic folder class to MyFolder and did some changes. While I had some syntactical errors I´ve got a "Broken product" in my Zope product folder and found the error log. After fixing those errors I was quite happy - but now the Product vanished from my products folder after restarting Zope :-((. Any idea what could be wrong here? I'm using Zope 2.4.2 on a Debian GNU/Linux system. I might note that this could be caused by the following side effect. I had trouble installing the PageTemplate Product which was also not presented in the Products folder. When restarting Zope I've got: # /etc/init.d/zope restart Restarting Zope...WARNING: Python C API version mismatch for module pyexpat: This Python has API version 1010, module pyexpat has version 1007. ........ done. While doing my debugging stuff I did not see this Warning message. But when my Product MyFolder seemed to be syntactically OK this warning reapeared - and PageTemplates was in my Products folder mytseriousely. This is kind of strange but it might be that the warning is a hint that one of my products can not be installed and now MyFolder took over the role of PageTemplates? I append my really first try in a tar file. Could somebody please give me a hint? Kind regards Andreas.