[Zope] server says "document contains no data"

Hi after long experimenting I finally succeeded in installing Zope with Zap as webserver. :-))) As I tried to go through the Quicktutorial I got a strange error. As I tried to add a new DTML Document from the main menu it took a long long time and finally it ended with the (netscape-)error: Document contains no data The same thing happened as I tried to add an image or a document from a file. Does anybody know where the problem is? Thank you stefan Thull