Less than 3 namespace error

[rafarui]

Traceback (most recent call last):
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/web.py", line 1511, in _execute
    result = yield result
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/gen.py", line 1055, in run
    value = future.result()
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/concurrent.py", line 238, in result
    raise_exc_info(self._exc_info)
  File "<string>", line 4, in raise_exc_info
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/gen.py", line 1063, in run
    yielded = self.gen.throw(*exc_info)
  File "/opt/anaconda3/lib/python3.6/site-packages/bokeh/server/views/autoload_js_handler.py", line 26, in get
    session = yield self.get_session()
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/gen.py", line 1055, in run
    value = future.result()
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/concurrent.py", line 238, in result
    raise_exc_info(self._exc_info)
  File "<string>", line 4, in raise_exc_info
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/gen.py", line 1063, in run
    yielded = self.gen.throw(*exc_info)
  File "/opt/anaconda3/lib/python3.6/site-packages/bokeh/server/views/session_handler.py", line 43, in get_session
    session = yield self.application_context.create_session_if_needed(session_id, self.request)
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/gen.py", line 1055, in run
    value = future.result()
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/concurrent.py", line 238, in result
    raise_exc_info(self._exc_info)
  File "<string>", line 4, in raise_exc_info
  File "/opt/anaconda3/lib/python3.6/site-packages/tornado/gen.py", line 1069, in run
    yielded = self.gen.send(value)
  File "/opt/anaconda3/lib/python3.6/site-packages/bokeh/server/contexts.py", line 185, in create_session_if_needed
    self._application.initialize_document(doc)
  File "/opt/anaconda3/lib/python3.6/site-packages/bokeh/application/application.py", line 179, in initialize_document
    h.modify_document(doc)
  File "/opt/anaconda3/lib/python3.6/site-packages/bokeh/application/handlers/function.py", line 134, in modify_document
    self._func(doc)
  File "/home/rafael/pyCarol/pycarol/luigi_extension/taskviewer.py", line 142, in plot_task
    cm = self.get_colormapper()
  File "/home/rafael/pyCarol/pycarol/luigi_extension/taskviewer.py", line 129, in get_colormapper
    return CategoricalColorMapper(factors=factors, palette=Category10[nb_factors])
KeyError: 1