[Fixed]-Including new app causing AttributeError: 'str' object has no attribute '_meta' in Python/Django app

You have a typo in your declaration of the through attribute of Subscription.category: “SubscritptionCategory” rather than “SubscriptionCategory”. Because of that, Django can’t find the model you’re referencing.

Note however that since you don’t define any extra fields on that through model, there’s not much point having it; your code would be simpler, and many of Django’s functions would work better, if you didn’t define it.