Error !

AttributeError: 'NoneType' object has no attribute 'url'

</%def> <%def name="renderSkoleArticle(item,skoletrinn=None)"> <% item_link = item.url() target = '' redir = '' if item.attr('redirect'): target = '_blank'
/var/limecms/gskolen2/gskolen-01/gskolen-inst-01/Products/LimeVirtualObject/LimeVirtualObject.py, line 86:
szurl = object.url()
/var/limecms/gskolen2/gskolen-01/gskolen-inst-01/Products/LimeAPI/LimeCore.py, line 885:
url = self._url(lang='%s' % langcode)
templates/default/functions/partials, line 32:
<%
templates/default/skolelist, line 71:
${partials.renderSkoleArticle(subitem,skoletrinn)}
templates/default/site, line 100:
${self.main_content()}
/srv/globalnodata/limecms/gskolen2/gskolen-01/lib/python2.7/site-packages/mako/runtime.py, line 860:
callable_(context, *args, **kwargs)
/srv/globalnodata/limecms/gskolen2/gskolen-01/lib/python2.7/site-packages/mako/runtime.py, line 835:
_exec_template(inherit, lclcontext, args=args, kwargs=kwargs)
/srv/globalnodata/limecms/gskolen2/gskolen-01/lib/python2.7/site-packages/mako/runtime.py, line 803:
**_kwargs_for_callable(callable_, data))
/srv/globalnodata/limecms/gskolen2/gskolen-01/lib/python2.7/site-packages/mako/template.py, line 443:
return runtime._render(self, self.callable_, args, data)
/var/limecms/gskolen2/gskolen-01/gskolen-inst-01/Products/LimeTemplate/LimeTemplate.py, line 704:
html = mytemplate.render(object=object, site=site, request=self.REQUEST, extra=extra.get('kwargs', None), **extra)