Crash on Quit(Direwolf/Mystcraft?)

[Varil]

First, Pastebin : http://pastebin.com/xukbj7mR

Context :

I loaded up my creative world to experiment with Mystcraft books a bit and spent about an hour dimension hopping and experimenting with world variables. I generated maybe 10ish ages, customized 3-4, and got myself thoroughly lost when I forgot to bring along Link books. In any case, everything *runs* okay, but it consistently crashes with the above log when I exit the game. The world still loads and saves as far as I can tell.

 

[Varil]

Rather than make a new thread, I'm just going to put another one here since it looks like Mystcraft is going to be my bane.

First, two Pastebins : http://pastebin.com/uQLK7FCj(Entering new Mystcraft world, game exited with "Internal Server Closed". This is a SSP world).
Number two : http://pastebin.com/dat94X1h(On my attempt to reload the world, same problem).