@ines I tried to run your code on an existing model but got an error message.
nlp = spacy.load('/Users/jdalgliesh/prodigy/model')
nlp.add_pipe(nlp.create_pipe('ner'))
nlp.to_disk('/Users/jdalgliesh/prodigy/model-with-empty-ner')
The error message:
Traceback (most recent call last):
File "add_ner.py", line 5, in <module>
nlp.to_disk('../w2v_nowac_spacy_ner')
File "/Users/arash/.pyenv/versions/prodigy/lib/python3.6/site-packages/spacy/language.py", line 621, in to_disk
util.to_disk(path, serializers, {p: False for p in disable})
File "/Users/arash/.pyenv/versions/prodigy/lib/python3.6/site-packages/spacy/util.py", line 503, in to_disk
writer(path / key)
File "/Users/arash/.pyenv/versions/prodigy/lib/python3.6/site-packages/spacy/language.py", line 619, in <lambda>
serializers[name] = lambda p, proc=proc: proc.to_disk(p, vocab=False)
File "nn_parser.pyx", line 892, in spacy.syntax.nn_parser.Parser.to_disk
File "/Users/arash/.pyenv/versions/prodigy/lib/python3.6/site-packages/spacy/util.py", line 503, in to_disk
writer(path / key)
File "nn_parser.pyx", line 883, in spacy.syntax.nn_parser.Parser.to_disk.lambda3
TypeError: 'bool' object is not subscriptable