Cell #3. Can't compile the student's code. Error: IndexError('list index out of range')

Hi Pradeep,

Not sure if this thread might help you, but they were suggesting getting a copy of your current notebook before getting the fresh version and then copying the solutions from the old to the new one. Not sure if that is exactly what you did.
Anyway try several times submitting and check any potential changes that you did in some of the graded code part.

Good luck,