Another battle? No, I didn't want to force another group to abandon the game. I'm not sure why it would be any different anyhow
EDIT: Just tried another game and started up just fine. I wonder what the problem was the first time
I believe if the file doesnt exist on our server, this will happen - but happen to ALL players.
If just one player has this happen as you seemed to have, its usually because the Launcher was unable to write the battle file (like, permissions or locked file or something)
I'll check the code anyway, its possible that its trying to move a file that doesnt exist yet (due to you just installing it, so the 'old' battlefile isnt there.)
Thanks for trying it again though - hope you have fun in the mod! =)