Error !

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

if not frontpage: frontpage = object.first('frontpage-6-6') %> ${ frontpage.render() }
templates/default/project, line 7:
${ frontpage.render() }
/var/limecms/imr/imr01/lib/python2.6/site-packages/Mako-1.0.1-py2.6.egg/mako/runtime.py, line 860:
callable_(context, *args, **kwargs)
/var/limecms/imr/imr01/lib/python2.6/site-packages/Mako-1.0.1-py2.6.egg/mako/runtime.py, line 835:
_exec_template(inherit, lclcontext, args=args, kwargs=kwargs)
/var/limecms/imr/imr01/lib/python2.6/site-packages/Mako-1.0.1-py2.6.egg/mako/runtime.py, line 803:
**_kwargs_for_callable(callable_, data))
/var/limecms/imr/imr01/lib/python2.6/site-packages/Mako-1.0.1-py2.6.egg/mako/template.py, line 443:
return runtime._render(self, self.callable_, args, data)
/var/limecms/imr/imr01/imr-inst/Products/LimeTemplate/LimeTemplate.py, line 702:
html = mytemplate.render(object=object, site=site, request=self.REQUEST, extra=extra.get('kwargs', None), **extra)