Course 3 week 4 'utf-8' codec can't decode byte 0x80 in position 0: invalid start byte I am getting this error

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I am doing course 3 and in week 4 I am getting this error ‘utf-8’ codec can’t decode byte 0x80 in position 0: invalid start byte after I submit my assignment. Before that I am not getting any errors in my notebook.

Please follow these steps to refresh your workspace and make a submission. Should the error not go away, click my name and message your notebook as an attachment.

I’m able to get full score for the notebook part for some reason. The staff have been notified about this. Please ping this topic if you don’t hear from the staff within 48 hours.