Error when using SimpleSeq2Seq

[natank1]

I Got this error

optional_input_placeholder = _to_list(_OptionalInputPlaceHolder().inbound_nodes[0].output_tensors)[0]
AttributeError: '_OptionalInputPlaceHolder' object has no attribute 'inbound_nodes'

When I trained SimpleSeq2Seq in python2.7.13

[ETMayberry]

I got the same error. It looks like it's trying to access a similar attribute in the superclass, Layer(object) called _inbound_nodes. I was able to move past this error by modifying the two incorrect references to inbound_nodes in engine.py:

line 842: optional_input_placeholder = _to_list(_OptionalInputPlaceHolder()._inbound_nodes[0].output_tensors)[0]

line 848: optional_input_placeholder = _to_list(_OptionalInputPlaceHolder()._inbound_nodes[0].output_tensors)[0]