Shape not compatible

[Lirry]

Hi!

Firstly, great tutorial!
I have a error when implementing the RESCAL model, that has to do with the tf.concat. When fitting the model, tensorflow does not recognize the shape? I am not new to programming but still learning so could be a made a nooby mistake.

Where the error appears:
unique_ent_indices = tf.unique(tf.concat(0, [self.head_input, self.tail_input]))[0]

Message from tensorflow:
ValueError: Shapes (2, ?) and () are incompatible

Any ideas?

Thanks!