I also have the same problem of grader error. My solution overall runs completely fine, achieves required loss and accuracy. I’ve also checked that auto-encoded images look completely fine.
I’ve tried just about everything I saw as suggested here - fallback runtime, strictly following the instructions for 2.8.0 tensorflow and keras installation - nothing works.
@alhimik, the assignment was recently updated to include the steps to help you work around the issue with the version mismatch with the grader.
If you are using the new version of the assignment, it should be downloading the model using the file name, final_model.h5
Some things to try:
Make sure you are using the latest version of the assignment (the one that downloads filename final_model.h5
Make sure you have followed the instruction in the assignment to go to Runtime > Restart Session and wait for the kernel to reconnect after you have pip installed tensorflow and keras version 2.8.0, and before you load temp_model.h5 and save final_model.h5
Make sure when you submit the assignment, you choose the “Replace file” link and select the downloaded file named final_model.h5