Matthias =?ISO-8859-1?Q?F=FCsting?= writes:

... As I create a folder with the name "icon", a error message came from Zope. --> Error Type: Bad Request Error Value: The id icon is invalid - it is already in use.

I think "icon" is a system-variable. "icon" is (in some way) part of Zope's management interface. Its value is used as the icon to the left of a description in the folders content view or the tree view.

I fear, you have to rename you folder (e.g. to "Icon" or "icons") (or massively change Zope's code). Dieter