During my Empathy Session I was messing around in the playground and using certain code examples, when you click the button to use the native parser, the entire screen goes blank and the only way to "escape" or go back is to refresh the page which sets you on the original landing example.

This seems to happen if you choose the example code first and then choose "Native" or if you choose "Native" on a different example code and switch to one of the ones not working.

The examples I've found that do this are:
-FIZZBUZZ.PY
-CLASSDEF.PY
-PHPV7.PHP
-JAVASCRIPT.JS