Grad-CAM and Overlay cannot be displayed successfully

[pangda72]

Hi @fitushar
Thank you for sharing such great repo.But when I run this program using my own data set and weights,I get the following error:

At the same time,Grad-CAM and Overlay cannot be displayed successfully,the results are shown below:

I printed the gradients and found that they were all 0.

I don't know what's wrong. Could you please give me some help?
Looking forward to your reply.
Thanks in advance.

Best.