AttributeError: 'Node' object has no attribute 'input_masks'

[spacemonqi]

As the original versions are deprecated, I am using:

Keras = 2.7.0
TensorFlow = 2.7.0
Python = 3.8.2

Running the code after fixing the error in #54 results in the following

---

--------- Epoch 1 -----------
Traceback (most recent call last):
File "Train_POS.py", line 69, in
model.fit(epochs=25)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/neuralnets/BiLSTM.py", line 392, in fit
self.trainModel()
File "/home/daniel/emnlp2017-bilstm-cnn-crf/neuralnets/BiLSTM.py", line 272, in trainModel
self.models[modelName].train_on_batch(nnInput, nnLabels)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/keras/engine/training.py", line 1727, in train_on_batch
logs = self.train_function(iterator)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/eager/def_function.py", line 828, in call
result = self._call(*args, **kwds)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/eager/def_function.py", line 871, in _call
self._initialize(args, kwds, add_initializers_to=initializers)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/eager/def_function.py", line 725, in _initialize
self._stateful_fn._get_concrete_function_internal_garbage_collected( # pylint: disable=protected-access
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/eager/function.py", line 2969, in _get_concrete_function_internal_garbage_collected
graph_function, _ = self._maybe_define_function(args, kwargs)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/eager/function.py", line 3361, in _maybe_define_function
graph_function = self._create_graph_function(args, kwargs)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/eager/function.py", line 3196, in _create_graph_function
func_graph_module.func_graph_from_py_func(
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/framework/func_graph.py", line 990, in func_graph_from_py_func
func_outputs = python_func(*func_args, **func_kwargs)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/eager/def_function.py", line 634, in wrapped_fn
out = weak_wrapped_fn().wrapped(*args, **kwds)
File "/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/framework/func_graph.py", line 977, in wrapper
raise e.ag_error_metadata.to_exception(e)
AttributeError: in user code:

/home/daniel/emnlp2017-bilstm-cnn-crf/venv_scratch/lib/python3.8/site-packages/tensorflow/python/keras/engine/training.py:805 train_function  *
    return step_function(self, iterator)
/home/daniel/emnlp2017-bilstm-cnn-crf/neuralnets/keraslayers/ChainCRF.py:357 sparse_loss  *
    mask = self._fetch_mask()
/home/daniel/emnlp2017-bilstm-cnn-crf/neuralnets/keraslayers/ChainCRF.py:303 _fetch_mask  *
    mask = self._inbound_nodes[0].input_masks[0]

AttributeError: 'Node' object has no attribute 'input_masks'

Any help would be much appreciated!