C4W3 assignment - grading problem of stderr

I got the following error when submitting the .h5 file.

There was a problem grading your submission. Check stderr for more details.

I also observed the similar as the topic improment-of-assignment-write-up that when trying 100 epochs, the loss went way below 320 but the generated animes were worse. Then I took the suggestion to train till the loss just went below 320, stopped at 32 epochs. The generated results were slightly better but still nothing like the example. The submission failed with the same error message.

Could anyone help me debugging please? Thanks!

Hello Lu,

can you share the screenshot of the error you got while submitting the file.

I also went through this post C4W3 assignment- mean loss to check whether I made the common mistakes. I couldn’t find any. is that possible to send you the notebook for a check, Deepti?

I don’t know whether this helps.
The encoder model summary is

The decoder model summary is

I managed to submit and pass the assignment. I didn’t change anything but retrained the model until the loss is below 290 (when the loss was around 310, the similarity was still above 0.6).
Still had no idea where the problem was. It will be great to know why.