Why am I getting a KeyError: 'scheduler' when trying to run a celery beat?

I am using celery in Django to periodically schedule tasks. Here are the files:

tasks.py

@periodic_task(run_every=timedelta(minutes=1))
def query():
...

celery.py

from __future__ import absolute_import, unicode_literals

from os import environ, path

from celery import Celery
from django.conf import settings

PROJECT_NAME = path.basename(path.dirname(__file__))
environ.setdefault('DJANGO_SETTINGS_MODULE', '%s.settings' % PROJECT_NAME)

app = Celery(PROJECT_NAME)
app.config_from_object('django.conf:settings')
app.autodiscover_tasks(lambda: settings.INSTALLED_APPS)

When I run

celery -A project worker

to start the worker, that executes fine. However, when I run

celery -A project beat

to start the beat scheduler, I get the following error:

KeyError: 'scheduler'

Why would this be occurring? I am using vagrant in PyCharm and accessing the server through vagrant ssh.

Update:

If I run

celery -A project worker --beat --scheduler django --loglevel=info

I get no error but no tasks are being received by the workers. So it looks like tasks are not being received for some reason.

Also adding

app.conf.beat_schedule = {
    "query": {
        "task": "query",
        "schedule": crontab(minute="*", hour="*", day_of_month='*')
    }
}

to celery.py and adding

@app.task(name="query")

to tasks.py does not work.