I'm running into this problem with the ZClasses tutorial draft that several other people on this list reported. Curiously, I found no reply with a solution. I followed the steps as described in the draft, and all seems to work as expected until I try to modify or manage a CD instance: In the manage screen of the instance, the "Properties" tab is not visible (although other tabs that I create, like index_html linked to "View" work well), and if I try to set the instance's variables via DTML as described in the draft, the changes have no effect. I get this using 2.0 a1 as well as with very recent CVS versions. I'm using Python 1.5.2. It doesn't matter if I use ZODB3 (using z2.py) or 2 (using serve.py). I tried this with an empty Zope instance, logged in as superuser and following the tutorial step by step. Perhaps this is trivial, and sombody could post a short note to the list. Gregor