Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
This comment is hidden because it contains spoiler information about the solution
Regarding the "Language undefined is not supported" message, I can elicit that response by pasting in a URL to a kata and trying to submit a solution prior to logging in and selecting a language.
Make sure you've logged in to codewars and selected a language before trying to solve a kata.
Which language are you using? They seemed fine for me earlier today while using Ruby.