PolygonCompany.country gives error

[zukangy]

Code:

from pipeline_live.data.polygon.fundamentals import PolygonCompany
from pipeline_live.engine import LivePipelineEngine
from pipeline_live.data.sources.iex import list_symbols
from zipline.pipeline import Pipeline

--- code for API setup

pipe = Pipeline(
columns={'country': PolygonCompany.country.latest
},
screen=country
)

eng = LivePipelineEngine(list_symbols)

eng.run_pipeline(pipe)

error message:

File "zipline/lib/_factorize.pyx", line 187, in zipline.lib._factorize.factorize_strings
File "zipline/lib/_factorize.pyx", line 222, in zipline.lib._factorize.factorize_strings
File "zipline/lib/_factorize.pyx", line 171, in zipline.lib._factorize.factorize_strings_impl
TypeError: '<' not supported between instances of 'str' and 'NoneType'

Is there a fix?

Best,