Владимир Хмурин

Вопрос решил, удалил из ArticleForm article_categories и все заработало!

Рабочий код в forms.py

class ArticleForm(forms.ModelForm):
    name = forms.CharField(widget=forms.TextInput(attrs={'class': 'form-control py-4'}))
    article = forms.CharField(widget=forms.TextInput(attrs={'class': 'form-control py-4'}))
    images = forms.ImageField(widget=forms.FileInput(attrs={'class': 'form-control py-4'}))
    urls = forms.CharField(widget=forms.TextInput(attrs={'class': 'form-control py-4'}))

    class Meta:
        model = Article
        fields = '__all__'
        widgets = {
            'name': forms.TextInput(attrs={'class': 'form-control py-4'}),
            'article': forms.TextInput(attrs={'class': 'form-control py-4'}),
            'images': forms.FileInput(attrs={'class': 'form-control py-4'}),
            'urls': forms.TextInput(attrs={'class': 'form-control py-4'}),
            'article_categories': forms.Select(attrs={'class': 'table table-sm', 'size': '3'})
        }