Course 5: Week 1: Music inference model (LSTM)

I have a found solution! After 100000000 attempts!
You just need to put :

LSTM_cell = LSTM(n_a, return_state = True)

before this line on code :

inference_model = music_inference_model(LSTM_cell, densor,reshaper, Ty = 50)

I have noticed that the input size was adding up after each run, so reseting the LSTM_cell solve the problem,