I'm getting this unexpected error. It appears in the launcher's log when you launch the game. It doesn't appear to prevent the game from launching but it does make me wonder what is going wrong. Here's the error, plus the first two previous lines. I'm using pastebin, because I'm not sure that the forum posting box will hold the correct formatting of the log text. Notice it's trying to do something with regard to 1.7.4 it seems, even though I'm trying to run version 1.8.1, which means it should not be having to do anything with any older version.
http://pastebin.com/raw.php?i=48aNHkpu