django makemigrationsができない

Question

djangoでアプリ制作をしようと
まずはmodelを作りmakemigrationsをしたいのですが
このエラーにずっと苦戦してます。。。

from django.db import models
from django.contrib.auth.models import User
from datetime import datetime

class Post(models.Model):
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    photo = models.ImageField(upload_to='media/', blank=True, null=True)
    caption = models.TextField(blank=True, null=True)
    likes = models.ManyToManyField(User, related_name='liker',blank=True)
    follow = models.ManyToManyField(User, related_name='follower')
    published_date = models.DateTimeField(auto_now_add=True)
    tag_name = models.CharField(max_length=10, blank=True, null=True)

    def __str__(self):
        return self.caption

class Comments(models.Model):
    comment = models.CharField(max_length=500)
    commenter = models.ForeignKey(User, on_delete=models.CASCADE,
                                   related_name='commenter')
    posted_id = models.ForeignKey(Post, on_delete=models.CASCADE)
    pub_date = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.commenter


class Favorites(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE, \
                              related_name='favorite_post')
    favorite_ppl = models.ForeignKey(User, on_delete=models.CASCADE,)



class Follow(models.Model):
    follower = models.ForeignKey(User, on_delete=models.CASCADE)


class Tags(models.Model):
    tag_name = models.ManyToManyField(Post)

from django.contrib import admin
from Sns.models import Post, Comments, Favorites

# Register your models here.

admin.site.register(Post)
admin.site.register(Comments)
admin.site.register(Favorites)

model,adminはこんな感じです。

File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/Users/rs0325/django/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "/Users/rs0325/django/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/rs0325/django/django/core/management/base.py", line 330, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/rs0325/django/django/core/management/base.py", line 371, in execute
    output = self.handle(*args, **options)
  File "/Users/rs0325/django/django/core/management/base.py", line 85, in wrapped
    res = handle_func(*args, **kwargs)
  File "/Users/rs0325/django/django/core/management/commands/makemigrations.py", line 164, in handle
    changes = autodetector.changes(
  File "/Users/rs0325/django/django/db/migrations/autodetector.py", line 43, in changes
    changes = self._detect_changes(convert_apps, graph)
  File "/Users/rs0325/django/django/db/migrations/autodetector.py", line 129, in _detect_changes
    self.new_apps = self.to_state.apps
  File "/Users/rs0325/django/django/utils/functional.py", line 48, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/Users/rs0325/django/django/db/migrations/state.py", line 208, in apps
    return StateApps(self.real_apps, self.models)
  File "/Users/rs0325/django/django/db/migrations/state.py", line 278, in __init__
    raise ValueError("\n".join(error.msg for error in errors))
ValueError: The field Sns.Comments.posted_id was declared with a lazy reference to 'sns.post', but app 'sns' isn't installed.
The field Sns.Favorites.post was declared with a lazy reference to 'sns.post', but app 'sns' isn't installed.

snsがインストールされていないということ？
ですがsetting.pyのinstalled_appの方にしっかり登録してあります。

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'django.contrib.sites',

    'rest_framework',
    'rest_framework.authtoken',

　　'Sns',

どなたか分かる方いましたら教えていただきたいです。

Answer 1

どこかの記述で"Sns"であるべきところが"sns"になっている（またはその逆）部分がありませんか？

Comments

[rs888]

今確認しましたがそういった部分は一切ありませんでした（ ; ; ）
何が原因なのでしょうか。。

Answer 2

下記のようにしたらどうなりますか？

# settings.py
INSTALLED_APPS = [
    # snip
    'sns',  # 'Sns'を小文字に
]

Comments

[rs888]

今試してみましたが
ModuleNotFoundError: No module named 'sns'　というエラーで返って来てしまいました（ ; ; ）

[hasami]

admin.pyのfromがSnsになっています。