Django-SEO issue

I've successfully installed Django-SEO, but when I try to limit the number of backends (I only need/want my admin to have 'path' and not the other three) I am met with the following error:

AttributeError at /admin/

'NoneType' object has no attribute '_meta'

I am using the documentation here: http://django-seo.readthedocs.org/en/latest/reference/definition.html#Meta.backends

seo.py

from rollyourown import seo

class AppMetadata(seo.Metadata):

    title = seo.Tag(head=True, max_length=68)

    description = seo.MetaTag(max_length=155)

    class Meta:

        backends = ('path',)

        #backends = ('path', 'modelinstance', 'model', 'view',) This works but includes all default backends

admin.py

from django.contrib import admin

from rollyourown.seo.admin import register_seo_admin

from localsite.seo import AppMetadata

register_seo_admin(admin.site, AppMetadata)

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To view this discussion on the web visit https://groups.google.com/d/msg/django-users/-/B1W0iR7aNokJ.
To post to this group, send email to django-users@googlegroups.com.
To unsubscribe from this group, send email to django-users+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/django-users?hl=en.