Chunk Generating Crash

Spigot #1163

I usually pregen my worlds so they load quicker with WorldBorder, and successfully genned an amplified world.

On our normal world, it crashes at 69.8% with the following error:

http://pastebin.com/PjrhxLNS

Furthermore, in our Spawn World with CleanRoomGenerator (generates a blank world) active, if we move too far out now the server crashes with the following error requiring our player data to be reset:

http://pastebin.com/MM4sTHyy


Any ideas?...

Chunk Generating Crash