It’s hard to tell without more context but it’s impossible that it prints anything after IndexError is raised.
So either your output comes from a print somewhere else in the code, or you line 416 belongs to a loop and that printed the first time and your list changed in between and it triggers an error the second time.
Whatever the problem is, you can debug a suspect list access with this kind of structure:
try:
<<anything using my_list[i]>>
except:
print(my_list)
Finally I found another way to solve the exercise.
In fact, Coding game restart the programme after each print, but sometimes, when the programme is printing something, it should use variables, but these ones are deleted with the restart.
It was the source of my problem : my_list[0][0] doesn’t exist after the printing.
I don’t know if it was clear, but if someone else has the same error, I hope my explications will be helpful.