@HAMINPANTS : http://codecombat.com/contribute/adventurer
For me there is a similar problem to Dungeon Arena: Failed to Rank on Sarven Brawl:
Error saving level session: 422 Unprocessable entity
Level got harder when i tried it again, but I didn’t get any of the level rewards.
Having now read this thread, I guess I should have waited for the email, but I noticed the level was up and went for it!