Hello happy Zopers, I'm currently trying to build a small & simple product, following (closely) advice from http://www.zope.org/Documentation/Books/ZDG/current/Products.stx The doc is clear and well done, but now I'm stuck on this : when I try to add some 'Candidat' (the meta_type of the product), I get from the ZMI a Zope Error Zope has encountered an error while publishing this resource. Error Type: TypeError Error Value: addForm() takes no arguments (1 given) etc... In the doc example, addForm is really defined with no argument, and I still don't see what knid of arg that ought to be. I'm still investigating. Grepping around current existing products doesn't help much since no installed product shows this very pattern (of an addForm function defined as in the zope doc). Thanks for your patience, Aurélien.