lemmatization issue

[gliwork]

Добрый день,
при попытке просто повторить код лемматизации из примера с израильским послом:
for token in doc.tokens:
token.lemmatize(morph_vocab)

print(doc.tokens[:5])
{_.text: _.lemma for _ in doc.tokens}

выскакивает диагностика:

AttributeError Traceback (most recent call last)
Cell In [7], line 2
1 for token in doc.tokens:
----> 2 token.lemmatize(morph_vocab)
4 print(doc.tokens[:5])
5 {_.text: _.lemma for _ in doc.tokens}

File C:\miniconda3\envs\Python\lib\site-packages\natasha\doc.py:38, in DocToken.lemmatize(self, vocab)
37 def lemmatize(self, vocab):
---> 38 self.lemma = vocab.lemmatize(self.text, self.pos, self.feats)

File C:\miniconda3\envs\Python\lib\site-packages\natasha\morph\vocab.py:173, in MorphVocab.lemmatize(self, word, pos, feats)
170 def lemmatize(self, word, pos, feats):
171 from .lemma import lemmatize
--> 173 return lemmatize(self, word, pos, feats)

File C:\miniconda3\envs\Python\lib\site-packages\natasha\morph\lemma.py:58, in lemmatize(vocab, word, pos, feats)
56 word = normal_word(word)
57 forms = vocab(word)
---> 58 form = best_form(forms, pos, feats)
59 if form:
60 return normal_word(form.normal)

File C:\miniconda3\envs\Python\lib\site-packages\natasha\morph\lemma.py:48, in best_form(forms, pos, feats)
45 if form.pos == pos and form.feats == feats:
46 return form
---> 48 sim = grams_sim(form.pos, form.feats, pos, feats)
49 if sim > max:
50 best = form

File C:\miniconda3\envs\Python\lib\site-packages\natasha\morph\lemma.py:39, in grams_sim(a_pos, a_feats, b_pos, b_feats)
38 def grams_sim(a_pos, a_feats, b_pos, b_feats):
---> 39 return pos_sim(a_pos, b_pos) + feats_sim(a_feats, b_feats)

File C:\miniconda3\envs\Python\lib\site-packages\natasha\morph\lemma.py:33, in feats_sim(a, b)
30 def feats_sim(a, b):
31 return sum(
32 a[] == b[]
---> 33 for _ in a.keys() & b.keys()
34 if _ in FEATS
35 )

AttributeError: 'NoneType' object has no attribute 'keys'
(jupyter выделяет b.keys() как проблему)
В чем может быть причина?

[gliwork]

it works fine in Colab though, something wrong with my machine probably