I have added backwards compatibility for the old python solution name on the very off chance this happens again.

Your function is called late_clock, but I recently changed it to be latest_clock but your code still remembers the old version. Change your function to latest_clock and it should be fine.

You can also back up your solution, click RESET, and then you will get the most recent state. Then paste your solution back, rename the funciton to latest_clock, and this should help.

Is the function name latest_clock or did you change it?