Как исправить ошибку 'bool' object has no attribute 'startswith', возникшую при использовании django_smart_selects?

Question

[tanyaa]

В модели Location раньше были поля типа CharField (закоменчены в коде)
Continent=models.CharField
Country=models.CharField
В форме все отображалось корректно и все работало.

После того, как попыталась использовать django-smart-selects
Появилась ошибка:
'bool' object has no attribute 'startswith'
site-packages\crispy_forms\templates\bootstrap3\uni_form.html, error at line 4
Line 4:

{% if include_media %}
{{ form.media }}
{% endif %}
ошибка в выделенной строчке.
Помогите,пожалуйста, разобраться, что произошло и как это исправить?

Models.py
class ListOfContinents(models.Model):

    id_Continent = models.AutoField(primary_key=True)
    Continent = models.CharField(max_length=200,unique=True) 

    def __str__(self):
        return '%s' % self.Continent

class ListOfCountries(models.Model):

    id_Country = models.AutoField(primary_key=True)
    Continent = models.ForeignKey(ListOfContinents, default=0, to_field='Continent',db_column='Continent')
    Country=models.CharField(max_length=200,unique=True)

    def __str__(self):
        return '%s' % self.Country



class Location(models.Model):

    #Continent=models.CharField(max_length=200,null=True, verbose_name='Континент')
    #Country=models.CharField(max_length=200,null=True, verbose_name='Страна')
    Continent=models.ForeignKey(ListOfContinents,to_field='Continent',db_column='Continent',verbose_name='Континент',null=True)
    Country = ChainedForeignKey(ListOfCountries,chained_field="Continent",
        chained_model_field="Continent",
        show_all=False,
        auto_choose=True,
        sort=True, 
        verbose_name='Страна',
        db_column='Country',
        to_field='Country',
        null=True)


Forms.py

class LocationForm (forms.ModelForm):
    class Meta:
        model = Location
        fields = ('Continent','Country')

    def __init__(self, *args, **kwargs):
        self.helper = FormHelper()
        self.helper.form_id = 'id-unitForm'
        # self.helper.form_class = 'blueForms'
        self.helper.form_class = 'form-horizontal'
        self.helper.label_class = 'col-lg-1'
        self.helper.field_class = 'col-lg-4'
        self.helper.form_method = 'post'
        # self.helper.form_action = 'submit_survey'

        self.helper.add_input(Submit('submit', 'Submit', css_class='btn btn-primary'))
        self.helper.add_input(Button('cancel', 'Cancel', css_class='btn-default', onclick="window.history.back()"))

        super(LocationForm , self).__init__(*args, **kwargs)

view.py
   
def Loc(request):
    if request.method == "POST":
        form_add = LocationForm(request.POST)
        if form_add.is_valid():
            
            Loc.save()
           
            return redirect('Loc_edit_full')
    else:
        form_add = LocationForm()
    return render(request, 'utest_base/Loc_add.html', {'form_add': form_add})

Comments

[Артём Белоусов]

Можно views.py?Думаю, проблема в нём

[tanyaa]

Артём Белоусов:
Вьюшку я не меняла, вроде в описании django-smart-selects про изменение вьюшки не было ничего=(

view.py: 
def Loc(request):
    if request.method == "POST":
        form_add = LocationForm(request.POST)
        if form_add.is_valid():
            
            Loc.save()
           
            return redirect('Loc_edit_full')
    else:
        form_add = LocationForm()
    return render(request, 'utest_base/Loc_add.html', {'form_add': form_add})

[tanyaa]

Артём Белоусов: Ошибка в файле site-packages\django\forms\widgets.py in absolute_path
В классе Media , в вот в этой части
def absolute_path(self, path, prefix=None):
if path.startswith(('http://', 'https://', '/'))
Но как это пофиксить не пойму =(
class Media:

class Media(object):
    def __init__(self, media=None, **kwargs):
        if media:
            media_attrs = media.__dict__
        else:
            media_attrs = kwargs

        self._css = {}
        self._js = []

        for name in MEDIA_TYPES:
            getattr(self, 'add_' + name)(media_attrs.get(name, None))

    def __str__(self):
        return self.render()

    def render(self):
        return mark_safe('\n'.join(chain(*[getattr(self, 'render_' + name)() for name in MEDIA_TYPES])))

    def render_js(self):
        return [
            format_html(
                '<script type="text/javascript" src="{}"></script>',
                self.absolute_path(path)
            ) for path in self._js
        ]

    def render_css(self):
        # To keep rendering order consistent, we can't just iterate over items().
        # We need to sort the keys, and iterate over the sorted list.
        media = sorted(self._css.keys())
        return chain(*[[
            format_html(
                '<link href="{}" type="text/css" media="{}" rel="stylesheet" />',
                self.absolute_path(path), medium
            ) for path in self._css[medium]
        ] for medium in media])

    def absolute_path(self, path, prefix=None):
        if path.startswith(('http://', 'https://', '/')):
            return path
        if prefix is None:
            if settings.STATIC_URL is None:
                # backwards compatibility
                prefix = settings.MEDIA_URL
            else:
                prefix = settings.STATIC_URL
        return urljoin(prefix, path)

    def __getitem__(self, name):
        "Returns a Media object that only contains media of the given type"
        if name in MEDIA_TYPES:
            return Media(**{str(name): getattr(self, '_' + name)})
        raise KeyError('Unknown media type "%s"' % name)

    def add_js(self, data):
        if data:
            for path in data:
                if path not in self._js:
                    self._js.append(path)

    def add_css(self, data):
        if data:
            for medium, paths in data.items():
                for path in paths:
                    if not self._css.get(medium) or path not in self._css[medium]:
                        self._css.setdefault(medium, []).append(path)

    def __add__(self, other):
        combined = Media()
        for name in MEDIA_TYPES:
            getattr(combined, 'add_' + name)(getattr(self, '_' + name, None))
            getattr(combined, 'add_' + name)(getattr(other, '_' + name, None))
        return combined