In the discussion app for groups and events the code button sets the default type to xml as seen here:
It should set the type to "markup" (or all depending on how ES handles this). While xml is important, HTML, JS, and CSS are used far more often. A while back I recall EasyDiscuss using xml as the default but then swapping over to markup. Plus a universal code type is much more versatile. I'm guessing the code type is still required?