AWSにデプロイしたDjangoアプリで発生する500Internalサーバーエラーを解消したい

AWSにdjangoをデプロイしました。

開発環境（http://127.0.0.1:8000/admin/）は問題なく表示されるのですが、AWSのElastic Beanstalkにデプロイすると、Internal Server Errorが発生してしまいます。

URLは　http://django-env.pk2mp6mrf8.ap-northeast-1.elasticbeanstalk.com/　です。

Pythonのバージョンが開発環境は3.6、AWSのほうは2.7なので、それが問題でしょうか？

他にもsettings.pyのDEBUG = True　→　DEBUG = Falseを試しましたが、変化はありません。

AWSのログを見ると、以下のようになっています。

[Sat Jun 09 10:37:48.764648 2018] [:error] [pid 27178] [remote 172.31.14.221:128] mod_wsgi (pid=27178): Target WSGI script '/opt/python/current/app/ebdjango/wsgi.py' cannot be loaded as Python module.
[Sat Jun 09 10:37:48.764679 2018] [:error] [pid 27178] [remote 172.31.14.221:128] mod_wsgi (pid=27178): Exception occurred processing WSGI script '/opt/python/current/app/ebdjango/wsgi.py'.
[Sat Jun 09 10:37:48.764694 2018] [:error] [pid 27178] [remote 172.31.14.221:128] Traceback (most recent call last):
[Sat Jun 09 10:37:48.764710 2018] [:error] [pid 27178] [remote 172.31.14.221:128]   File "/opt/python/current/app/ebdjango/wsgi.py", line 16, in <module>
[Sat Jun 09 10:37:48.764733 2018] [:error] [pid 27178] [remote 172.31.14.221:128]     application = get_wsgi_application()
[Sat Jun 09 10:37:48.764741 2018] [:error] [pid 27178] [remote 172.31.14.221:128]   File "/opt/python/run/venv/local/lib/python2.7/site-packages/django/core/wsgi.py", line 13, in get_wsgi_application
[Sat Jun 09 10:37:48.764755 2018] [:error] [pid 27178] [remote 172.31.14.221:128]     django.setup()
[Sat Jun 09 10:37:48.764761 2018] [:error] [pid 27178] [remote 172.31.14.221:128]   File "/opt/python/run/venv/local/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
[Sat Jun 09 10:37:48.764780 2018] [:error] [pid 27178] [remote 172.31.14.221:128]     apps.populate(settings.INSTALLED_APPS)
[Sat Jun 09 10:37:48.764786 2018] [:error] [pid 27178] [remote 172.31.14.221:128]   File "/opt/python/run/venv/local/lib/python2.7/site-packages/django/apps/registry.py", line 78, in populate
[Sat Jun 09 10:37:48.764796 2018] [:error] [pid 27178] [remote 172.31.14.221:128]     raise RuntimeError("populate() isn't reentrant")
[Sat Jun 09 10:37:48.764808 2018] [:error] [pid 27178] [remote 172.31.14.221:128] RuntimeError: populate() isn't reentrant