https://docs.python.org/2/library/collections.html#collections.OrderedDict

?

Reloading shouldn't help because this is the code runner saying no output (stdout/stderr) was produced by the submitted code.
Most likely the solution crashed.

Someone might be able to help if you post your solution here, marking as a spoiler.

That's a CW issue, not a Kata issue. Try reloading the page.