What is the cause of error in django admin?

Question

Django

For the Post model, the default manager is overridden

#models.py
class ObjectsOnManager(models.Manager):
    def get_queryset(self):
        return super(ObjectsOnManager, self).get_queryset().filter(status='on')


class OnOffStatusModel(models.Model):
    ON = 'on'
    OFF = 'off'
    STATUS_CHOICES = (
        (ON, 'Показывать'),
        (OFF, 'Не показывать'),
    )
    status = models.CharField("Статус", max_length=15, choices=STATUS_CHOICES, default=ON)
    objects_on = ObjectsOnManager()
    objects = models.Manager()

    class Meta:
        abstract = True

class Post(OnOffStatusModel):
    # определяем поля
    ......

Further, in order to see all posts in the admin panel, I override the get_queryset method:

#admin.py
class PostAdmin(admin.ModelAdmin):
    form = PostImageControlForm
    fields = ('count', 'status',  'image',  'title', 'descript', 'body', 'main_post', )
    list_display = ('title', 'main_post', 'count',)
    list_editable = ('main_post', 'status')
    list_filter = ('category', 'main_post', 'status')

    def get_queryset(self, request):
        return Post.objects.all()

Now, when editing the model from the post list page (i.e. via list_editable)
, the form validation error "Please fix the error below." pops up, and no fields are highlighted. I dug around in the debugger and eventually found an error in the formset in the changelist_view
[{'id': ['Choose the correct option. Your variant is not among the allowed values.']}, {}, {}, {}, {}]
I can't figure out why it pops up and what needs to be fixed...