Can't join a challenge room

I just tried to accept a challenge, but when I attempted to enter the room I was unable to actually join. I saw two messages on the main screen, the first was that my opponent was ready. The second read "Error: Failed to join room: name 'Move' is not defined." When I click "I'm Ready" in the bottom right, I get another error message that reads "Error: You must join the room first (click Join Room), only there is nowhere to click Join Room.
Some added information: I am a relatively new user, level 2. I have a few pieces of very basic equipment equipped (heavy boots, brass knuckles, greater healing potion), and my moveset is currently pretty basic as well: Light attack, Heavy Attack, Passing Attack (for a total cost of 25/25). I can't really imagine what about my character might be breaking the room or causing this move-name error. Please let me know if I can provide any other information.