[Zope] AttributeError __getslice__ from Zope Construction Kit book

[hpinson@indepthl.com]

Hello.  I've been through the Zope "Web Application  Construction 
Kit" book tutorial, chapter 5, "Building a Portal and Adding Serices" 
 "Creating a Type with ZClasses", twice now.

Each time, when attempting to add the new ZClass object in a user 
folder, this error is generated:

Error Type 
AttributeError

Error Value 
__getslice__

Does anyone have any sense of what this means and how to fix it?

My Zope is 2.6.0 running on Redhat 8.

Thanks.

Harlow Pinson
Indepth Learning
Email: hpinson@indepthl.com 
Web: http://www.indepthl.com
Voice: 505-994-2135
FAX: 208-475-7678