[Zope] PageTemplates len() of unsized object

[Giampiero Benvenuti]

Hello list,

after the upgrade from zope2.9.7 to 2.10.6 i get this error in the  
event log:

2008-05-24T09:31:32 ERROR Zope.SiteErrorLog http://myurl/error_log/manage_main
Traceback (innermost last):
   Module ZPublisher.Publish, line 119, in publish
   Module ZPublisher.mapply, line 88, in mapply
   Module ZPublisher.Publish, line 42, in call_object
   Module Shared.DC.Scripts.Bindings, line 313, in __call__
   Module Shared.DC.Scripts.Bindings, line 350, in _bindAndExec
   Module Products.PageTemplates.PageTemplateFile, line 129, in _exec
   Module Products.PageTemplates.PageTemplate, line 89, in pt_render
   Module zope.pagetemplate.pagetemplate, line 117, in pt_render
   Module zope.tal.talinterpreter, line 271, in __call__
   Module zope.tal.talinterpreter, line 346, in interpret
   Module zope.tal.talinterpreter, line 379, in do_startEndTag
   Module zope.tal.talinterpreter, line 412, in do_startTag
TypeError: len() of unsized object


If I click on ZMI "error_log" i just get:

Error Type: TypeError
Error Value: len() of unsized object

Can someone explain to me what is going on?

Your help is very much appreciated.

Giampiero