Line 997 of django.contrib.admin.options.py defines:
inline_instances = self.get_inline_instances(request, None)
In FeinCMS the signature is:
def get_inline_instances(self, request):
So the calling method dies with a:
get_inline_instances() takes exactly 2 arguments (3 given)
when you go to add items in the admin interface.
I think changing the signature to:
def get_inline_instances(self, request, obj=None):
will fix it