C4_w1_3.3: alueError: operands could not be broadcast together with shapes

I’ve read many of the posts on this problem and I still do not understand what I am doing wrong.

I am still stuck with the below error and would appreciate any help. Thanks!

ValueError                                Traceback (most recent call last)
<ipython-input-36-7e580406a9e8> in <module>
      6                "stride": 2}
      7 
----> 8 Z, cache_conv = conv_forward(A_prev, W, b, hparameters)
      9 z_mean = np.mean(Z)
     10 z_0_2_1 = Z[0, 2, 1]

<ipython-input-26-70566c27a93f> in conv_forward(A_prev, W, b, hparameters)
    109                     # a = conv_single_step(a_slice_prev, weights, biases)
    110                     # print(f"a is {a}")
--> 111                     Z[i, h, w, c] = conv_single_step(a_slice_prev, weights, biases)
    112 
    113     # YOUR CODE ENDS HERE

<ipython-input-4-c5bec9c8f2fe> in conv_single_step(a_slice_prev, W, b)
     26     # p rint(f"shape W: {W.shape}")
     27     # print(f"shape b: {b.shape}")
---> 28     s = np.multiply(a_slice_prev, W)
     29     Z = np.sum(s)
     30     Z += np.float64(b)

ValueError: operands could not be broadcast together with shapes (3,0,4) (3,3,4) 

Maybe this guide helps.

Thanks so much! I found my mistake. I was looping over n_H_prev and n_W_prev