Captured logging:
      INFO:pymorphy2.opencorpora_dict.wrapper:Loading dictionaries from /home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/pymorphy2_dicts/dataINFO:pymorphy2.opencorpora_dict.wrapper:format: 2.4, revision: 393442, updated: 2015-01-17T16:03:56.586168ERROR:django.request:Internal Server Error: /salary/assignment/register
      Traceback (most recent call last):
        File "/home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner
          response = get_response(request)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/django/core/handlers/base.py", line 115, in _get_response
          response = self.process_exception_by_middleware(e, request)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/django/core/handlers/base.py", line 113, in _get_response
          response = wrapped_callback(request, *callback_args, **callback_kwargs)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-salary/salary/urls.py", line 96, in salary_view
          result = salary_controller.process_request(request)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/m3/actions/__init__.py", line 1074, in process_request
          result = self._invoke(request, action, stack, suffix)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-core/web_bb/core/base/controller.py", line 698, in _invoke
          result = super()._invoke(request, action, stack, suffix)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-core/web_bb/core/base/controller.py", line 511, in _invoke
          return super()._invoke(request, action, stack, suffix)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/m3/actions/__init__.py", line 1011, in _invoke
          action, request, context, stack, suffix=suffix)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-core/web_bb/core/base/controller.py", line 494, in _process_action
          action, request, context, stack, suffix)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/m3/actions/__init__.py", line 1038, in _process_action
          response = action.run(request, context)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-salary/salary/core/orders/api.py", line 1167, in sign_register_request
          return fn(pack_instance, request, context)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-salary/salary/core/slr_registers/assignment/actions.py", line 335, in request_register
          return super(AssignmentPack, self).request_register(request, context)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-salary/salary/core/slr_registers/actions.py", line 271, in request_register
          request, context, record, False)
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-salary/salary/core/slr_registers/assignment/actions.py", line 384, in validate_row
          candidate_ids=cand_id and [cand_id] or None):
        File "/home/dinar/.virtualenvs/web_bb_app_py36/src/web-bb-salary/salary/core/payroll_register/mutex.py", line 165, in payroll_mutex_exists
          if django_cache.keys(emp_pattern.format(ent_id=ent_id,
        File "/home/dinar/.virtualenvs/web_bb_app_py36/lib/python3.6/site-packages/django/core/cache/__init__.py", line 98, in __getattr__
          return getattr(caches[DEFAULT_CACHE_ALIAS], name)
      AttributeError: 'LocMemCache' object has no attribute 'keys'