getting a value error while defining a Bi-LTSM CRF model, please help thanks [closed]

Question

I am working on a named entity recognition model using Bi-LTSM CRF.I got a value error while defining the model. The error says (Could not interpret initializer identifier: 14). The code is below.

# Model definition
input = Input(shape=(MAX_LEN,))
model = Embedding(input_dim=n_words+2, output_dim=EMBEDDING, # n_words + 2 (PAD & UNK)
                  input_length=MAX_LEN, mask_zero=True)(input)  
model = Bidirectional(LSTM(units=50, return_sequences=True,
                           recurrent_dropout=0.1))(model)  # variational biLSTM
model = TimeDistributed(Dense(50, activation="relu"))(model)  # a dense layer as suggested by neuralNer
crf = CRF(n_tags+1)  # CRF layer, n_tags+1(PAD)
out = crf(model)  # output

model = Model(input, out)
model.compile(optimizer="rmsprop", loss=crf.loss, metrics=[crf.accuracy])

model.summary()

The is the error message, could you please help me figure out what I am doing wrong here? Thanks.

ValueError                                Traceback (most recent call last)
<ipython-input-28-d288958649dc> in <module>
      6                            recurrent_dropout=0.1))(model)  # variational biLSTM
      7 model = TimeDistributed(Dense(50, activation="relu"))(model)  # a dense layer as suggested by neuralNer
----> 8 crf = CRF(n_tags+1)  # CRF layer, n_tags+1(PAD)
      9 out = crf(model)  # output
~\AppData\Local\Continuum\anaconda3\lib\site-packages\tf2crf\crf.py in __init__(self, chain_initializer, **kwargs)
     34     def __init__(self, chain_initializer="orthogonal", **kwargs):
     35         super(CRF, self).__init__(**kwargs)
---> 36         self.chain_initializer = tf.keras.initializers.get(chain_initializer)
     37         self.transitions = None
     38         self.supports_masking = True