Haystack not working after upgrading to django 1.7

Question

I have django haystack 2.0.0 with whoosh setup like this

HAYSTACK_CONNECTIONS = {
    'default': {
        'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine',
        'PATH': '/home/kbuzz/whoosh_index',
        'EXCLUDED_INDEXES': ['<movies.search_indexes.EventIndex object at 0x7f445fff0ef0>','<movies.search_indexes.EventIndex object at 0x7fd07ca3ef58>','<movies.search_indexes.EventIndex object at 0x7f0d2cfecf58>','<movies.search_indexes.EventIndex object at 0x7f990700bf58>'],
    },
}

but rebuild_index and update_index doesn't work, clear_index works though.

I have search_indexes.py for Article Model setup

import datetime
from haystack import indexes
from search.base_search_index import BaseSearchIndex
from articles.models import Article

and the BaseSearchIndex

import datetime
from django.db.models import Q
from haystack import indexes


class BaseSearchIndex(indexes.SearchIndex):
    text = indexes.CharField(document=True, use_template=True)
    html = indexes.CharField(use_template=True, indexed=False)
    json = indexes.CharField(use_template=True, indexed=False)
    slug = indexes.CharField()
    #pk_xapian = indexes.IntegerField(model_attr='pk')
    i = indexes.IntegerField(model_attr='pk')

    def prepare_slug(self, obj):
        return u'unique%sunique' % obj.slug

    def get_updated_field(self):
        return 'modified'

    def index_queryset(self, using=None):
        """Used when the entire index for model is updated."""
        today = datetime.date.today()
        return self.get_model().objects.filter(
            Q(visible=True) &
            Q(publish__lte=today) &
            (Q(expires__isnull=True) | Q(expires__gte=today))
        ).distinct()

    def prepare(self, obj):
        today = datetime.datetime.now()
        data = super(BaseSearchIndex, self).prepare(obj)
        weeks = (today - obj.created).days / 7 + 1
        data['boost'] = 1 + (1.0 / weeks)
        return data

    def get_list_for_multivalue_field(self, value):
        if len(value) == 0:
            return []
        elif len(value) == 1:
            return [value[0],]
        return value

class ArticleIndex(BaseSearchIndex, indexes.Indexable):

    area = indexes.IntegerField(null=True)
    categories = indexes.MultiValueField(null=True)
    hot = indexes.BooleanField(model_attr='is_hot')

    def prepare_area(self, obj):
        if obj.area_id:
            return obj.area_id
        return -1

    def prepare_categories(self, obj):
        cats = []
        for category in obj.categories.all():
            cats.extend([c.id for c in category.get_ancestors(include_self=True)])
        return self.get_list_for_multivalue_field(cats)

    def get_model(self):
        return Article

with the Article model

class Article(BaseItemModel):
    area = TreeForeignKey(Area, blank=True, null=True,)
    categories = TreeManyToManyField(Category)
    #imdb_id = models.CharField(max_length=255, blank=True, help_text="Used only for Series and Movie Reviews")
    #tags = models.ManyToManyField(Tag, blank=True, null=True)
    parent = models.ForeignKey(Movie, blank=True, verbose_name='Parent Movie', null=True, help_text="Used only for Series and Movie Reviews")
    rating = models.IntegerField(blank=True, default=0)
    editor_pick = models.BooleanField(default=False,)
    author = models.CharField(max_length=255, blank=True,)
    html = RichTextUploadingField(blank=True, null=True,)
    #html_edited = RichTextUploadingField(blank=True, null=True,)

    def share_content(self):
        html = self.html
        if not html:
            html = self.content
        return html.replace('"', "'").strip()

    @models.permalink
    def get_absolute_url(self):
        return ('article_detail', (), {'slug': self.slug})

when I run update_index I get this error message

Traceback (most recent call last):
  File "manage.py", line 11, in <module>
    execute_from_command_line(sys.argv)
  File "/home/kbuzz/webapps/kenyabuzz/lib/python2.7/Django-1.7.10-py2.7.egg/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/home/kbuzz/webapps/kenyabuzz/lib/python2.7/Django-1.7.10-py2.7.egg/django/core/management/__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/kbuzz/webapps/kenyabuzz/lib/python2.7/Django-1.7.10-py2.7.egg/django/core/management/base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/home/kbuzz/webapps/kenyabuzz/lib/python2.7/Django-1.7.10-py2.7.egg/django/core/management/base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "/home/kbuzz/lib/python2.7/haystack/management/commands/update_index.py", line 184, in handle
    return super(Command, self).handle(*items, **options)
  File "/home/kbuzz/webapps/kenyabuzz/lib/python2.7/Django-1.7.10-py2.7.egg/django/core/management/base.py", line 503, in handle
    label_output = self.handle_label(label, **options)
  File "/home/kbuzz/lib/python2.7/haystack/management/commands/update_index.py", line 210, in handle_label
    self.update_backend(label, using)
  File "/home/kbuzz/lib/python2.7/haystack/management/commands/update_index.py", line 256, in update_backend
    do_update(backend, index, qs, start, end, total, self.verbosity)
  File "/home/kbuzz/lib/python2.7/haystack/management/commands/update_index.py", line 78, in do_update
    backend.update(index, current_qs)
  File "/home/kbuzz/lib/python2.7/haystack/backends/whoosh_backend.py", line 189, in update
    self.log.error(u"%s while preparing object for update" % e.__name__, exc_info=True, extra={
AttributeError: 'UnknownFieldError' object has no attribute '__name__'