Not enough values to unpack (expected 2, got 1)

Hello! I faced with this problem when I try to run command python manage.py qcluster:

[Q] INFO Q Cluster-21177 starting.
[Q] INFO Process-1:1 ready for work at 21181
[Q] INFO Process-1:2 ready for work at 21182
[Q] INFO Process-1:3 ready for work at 21183
[Q] INFO Process-1:4 ready for work at 21184
[Q] INFO Process-1:5 monitoring at 21185
[Q] INFO Process-1 guarding cluster at 21180
[Q] INFO Process-1:6 pushing tasks at 21186
[Q] INFO Q Cluster-21177 running.
[Q] INFO Enqueued 2
[Q] INFO Process-1 created a task from schedule [check_achievements_monthly]
[Q] INFO Process-1:1 processing [two-nineteen-may-pasta]
[Q] ERROR Failed [two-nineteen-may-pasta] - not enough values to unpack (expected 2, got 1)

I use Python 3.7, Django 2.0.7

from datetime import datetime
from django.contrib.auth.models import User
from django_q.tasks import schedule
from pytz import timezone

from achievements.models import Achievement, UserAchievement


def check_ach(*args, **kwargs):
    for achievement in Achievement.objects.filter(period=args[0]):
        for user in User.objects.all():
            try:
                user_achievement = achievement.users_achievements.get(user=user)
            except UserAchievement.DoesNotExist:
                user_achievement = None

            if user_achievement and user_achievement.max_amount_reached:
                continue  # user already has maximal amount of that achievement - skip

            if achievement.is_earned(user):
                UserAchievement.objects.create(achievement=achievement, user=user)


schedule(check_ach,'MONTHLY', name='check_achievements_monthly', schedule_type='M', next_run=datetime.now().astimezone(timezone('Europe/Kiev')))

Can you help me with this issue?

[GodMode-On]

@mm-matthias @bronte2k7 @nastyaDjo I fixed it: in task pass not function instance, but path to it as str. For example: 'users.emails.send_email_message' instead of send_email_message

[mm-matthias]

I see this issue when requeing a failed task via the admin panel.