Hi @dada_Lai, I have tried to reproduce this bug on Colab, but it works fine in my notebook. You can find my notebook at Google Colab 7 . And, you can reload the model in a separate notebook at Google Colab 2. To run the second notebook, you need to copy the model produced by the first notebook to the workspace of the second notebook via mounting Google Drive. If you have any questions please let me know it.