title: Exception running celery
body: <p>I am trying to integrate celery version 4.2 in a django project. As per the docs I have done the changes in <strong>init</strong>.py and celery.py but when I run celery with:</p>
  
  <pre><code>python -m celery -A instaguide beat -l debug 
  </code></pre>
  
  <p>I get the exception below. I am not sure what it is missing. The only CELERY_ setting that I have defined in my project.settings is CELERY_BROKER_URL and it doesn't complain about not connecting to broker. So it is something else that I am missing either in my settings or somewhere else. Any clues?</p>
  
  <pre><code>celery-worker    | k (most recent call last):
  celery-worker    |   File "/usr/local/lib/python2.7/runpy.py", line 174, in _run_module_as_main
  celery-worker    |     "__main__", fname, loader, pkg_name)
  celery-worker    |   File "/usr/local/lib/python2.7/runpy.py", line 72, in _run_code
  celery-worker    |     exec code in run_globals
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/__main__.py", line 20, in &lt;module&gt;
  celery-worker    |     main()
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/__main__.py", line 16, in main
  celery-worker    |     _main()
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/celery.py", line 322, in main
  celery-worker    |     cmd.execute_from_commandline(argv)
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/celery.py", line 496, in execute_from_commandline
  celery-worker    |     super(CeleryCommand, self).execute_from_commandline(argv)))
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/base.py", line 275, in execute_from_commandline
  celery-worker    |     return self.handle_argv(self.prog_name, argv[1:])
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/celery.py", line 488, in handle_argv
  celery-worker    |     return self.execute(command, argv)
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/celery.py", line 420, in execute
  celery-worker    |     ).run_from_argv(self.prog_name, argv[1:], command=argv[0])
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/worker.py", line 223, in run_from_argv
  celery-worker    |     return self(*args, **options)
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/base.py", line 238, in __call__
  celery-worker    |     ret = self.run(*args, **kwargs)
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/bin/worker.py", line 257, in run
  celery-worker    |     **kwargs)
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/worker/worker.py", line 96, in __init__
  celery-worker    |     self.app.loader.init_worker()
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/loaders/base.py", line 114, in init_worker
  celery-worker    |     self.import_default_modules()
  celery-worker    |   File "/usr/local/lib/python2.7/site-packages/celery/loaders/base.py", line 108, in import_default_modules
  celery-worker    |     raise response
  celery-worker    | celery.schedules.ParseException: empty filter
  </code></pre>