def remove_old_countdowns_messages(apps, schema_editor):
    """
    Remove old countdowns and messages created by 2.0 from projector elements which are unusable in 2.1.
    """
    Projector = apps.get_model('core', 'Projector')
    projector = Projector.objects.get(pk=1)
    projector_config = projector.config
    for key, value in list(projector.config.items()):
        if value.get('name') in ('core/countdown', 'core/message'):
            del projector_config[key]
    projector.config = projector_config
    projector.save(skip_autoupdate=True)
