So I was running around getting some of my forestry stuff done when I realised I needed to recharge some of my stuff (grafter). Since my base is quite large and has multiple levels, I had begun using a warp book to move around quickly instead of jetpacking around since it was already my nether portal and it costs nothing. However, upon opening my warp book, my game crashed to desktop. Considering that this had already happened early today, I simply re-launched the pack and attempted to play again. It was then that I discovered that my world was no longer in the selection when choosing world. I have checked the files and the world save is still there, and I know it couldn't have been deleted anyway because I still have around 70 lives.
Here is the pastebin for the crash: http://pastebin.com/hkfQ1qDg
Here is the crash from earlier on (the one that didnt seem to break anything): http://pastebin.com/5bKvt5gM