LanguageModelFeaturizer.py token has to attribute text, no attribute set

I try to employ bert from language model featurizer. when i train rasa, the error occured AttributeError: ‘str’ object has no attribute ‘set’

i saw the problem came from

rasa\nlu\featurizers\dense_featurizer\lm_featurizer.py", line 348, AttributeError: ‘str’ object has no attribute ‘text’

where

split_token_ids, split_token_strings = self._lm_tokenize(token.text)

How can i solve this?

I try to remove .text But i got stuck in the line 363

said that token has no attribute .set

Can anybody help?

Thankyou