Method sometimes returns list, sometimes queryset
apps/discussion/models.py, method for_similar_objects of class CommentNodeManager. If objects is false, then an empty list is returned, otherwise a queryset is returned. Later processing assumes a queryset.
Change "return " to "return self.none()", it fixes it.
It might be a problem when there are no posts/comment nodes (as there is when a new users sets up byteflow). Actually there was a draft post, but no approved posts. the problem happened when I visited the front page of the blog as anonymous.
Saw problem in my old version and in latest version pulled this weekend from bitbucket.