Snow Block update problem???

I honestly have no clue what the hell is going on. This happens only sometime not often, in total I've gotten about 5 of these crashes in the past week. But it's really annoying and I'd like to know what is this. http://pastebin.com/VKAnHyPa
That's the link to the error, I can't put the whole error because it's too much.
I'll post more if anything.

Is this a world error or a plugin error?