Train_happy_sad_model error

Course Q&A TensorFlow Developer Professional Introduction to TF for Artificial Intelligence ...
1

Hello ,
I failed train_happy_sad_model and got the below error:
Failed test case: hist has incorrect type.
Expected:
<class ‘keras.callbacks.History’>,
but got:
<class ‘NoneType’>.
But each step works well and type(hist) output is
keras.callbacks.History.
Could you please advise?

2

Please see assignment troubleshooting tips here. Did you look at the 4th step?