n_vocab AttributeError

[SODAsoo07]

Traceback (most recent call last):
File "train.py", line 973, in
model = build_model().to(device)
File "train.py", line 816, in build_model
n_vocab=_frontend.n_vocab,
AttributeError: 'NoneType' object has no attribute 'n_vocab'

If you change the frontend of hparams.py to jp and run train.py, the error is output