Traceback (most recent call last):
  File "/dist-packages/trytond/protocols/jsonrpc.py", line 108, in _marshaled_dispatch
    response['result'] = dispatch_method(method, params)
  File "/dist-packages/trytond/protocols/jsonrpc.py", line 147, in _dispatch
    res = dispatch(*args)
  File "/dist-packages/trytond/protocols/dispatcher.py", line 155, in dispatch
    res = getattr(obj, method)(*args_without_context, **kargs)
  File "/dist-packages/trytond/model/modelworkflow.py", line 113, in workflow_trigger_validate
    instance_obj.validate(instance, signal=signal)
  File "/dist-packages/trytond/workflow/workflow.py", line 222, in validate
    force_running=force_running)
  File "/dist-packages/trytond/workflow/workflow.py", line 334, in process
    res = self._split_test(workitem, activity.split_mode, signal)
  File "/dist-packages/trytond/workflow/workflow.py", line 467, in _split_test
    self._join_test(transition, instance)
  File "/dist-packages/trytond/workflow/workflow.py", line 479, in _join_test
    'state': 'active',
  File "/dist-packages/trytond/workflow/workflow.py", line 313, in create
    self.process(workitem)
  File "/dist-packages/trytond/workflow/workflow.py", line 334, in process
    res = self._split_test(workitem, activity.split_mode, signal)
  File "/dist-packages/trytond/workflow/workflow.py", line 467, in _split_test
    self._join_test(transition, instance)
  File "/dist-packages/trytond/workflow/workflow.py", line 479, in _join_test
    'state': 'active',
  File "/dist-packages/trytond/workflow/workflow.py", line 313, in create
    self.process(workitem)
  File "/dist-packages/trytond/workflow/workflow.py", line 334, in process
    res = self._split_test(workitem, activity.split_mode, signal)
  File "/dist-packages/trytond/workflow/workflow.py", line 467, in _split_test
    self._join_test(transition, instance)
  File "/dist-packages/trytond/workflow/workflow.py", line 479, in _join_test
    'state': 'active',
  File "/dist-packages/trytond/workflow/workflow.py", line 313, in create
    self.process(workitem)
  File "/dist-packages/trytond/workflow/workflow.py", line 334, in process
    res = self._split_test(workitem, activity.split_mode, signal)
  File "/dist-packages/trytond/workflow/workflow.py", line 445, in _split_test
    if self._activate_transition(workitem, transition, signal):
  File "/dist-packages/trytond/workflow/workflow.py", line 434, in _activate_transition
    return test_fct(model_obj.browse(workitem.instance.res_id))
TypeError: 'Function' object is not callable