Riya can I know from where are you opening these assignment notebooks, because I recently address a url issue related to the same assignment and I remember it was not like this. Can you confirm if you have not edited any of the cells by mistake or not opened from any other source other than program assignment page of the respective course week’s assignment.
Please make sure to read the program assignment page carefully and follow instructions given in the assignment.
Can you share the screenshot where it mentions module error as it shows the cell run successfully.
If there was module error, it will show error log once you run the cell. But in the image it shows you cell run successfully but with a message log infront of the particular file.
I also noticed there are two colab browser open where one mentions copy and another your assignment, so make sure you close the one you are not working on.
Also I noticed that your changes are not getting autosaved, can I know the reason for the that.