Ticking memory connection

java.lang.NullPointerException
	at net.minecraft.world.chunk.Chunk.func_76592_a(Chunk.java:758)
	at net.minecraft.world.World.func_72832_d(World.java:559)
	at net.minecraft.world.World.func_94575_c(World.java:721)
	at vazkii.tinkerer.common.item.kami.tool.ToolHandler.removeBlockWithDrops(ToolHandler.java:108)
	at vazkii.tinkerer.common.item.kami.tool.ToolHandler.removeBlocksInIteration(ToolHandler.java:67)
	at vazkii.tinkerer.common.item.kami.tool.ItemIchorPickAdv.onBlockStartBreak(ItemIchorPickAdv.java:98)
	at net.minecraft.item.ItemInWorldManager.func_73084_b(ItemInWorldManager.java:300)
	at net.minecraft.item.ItemInWorldManager.func_73082_a(ItemInWorldManager.java:240)
	at net.minecraft.network.NetServerHandler.func_72510_a(NetServerHandler.java:502)
	at net.minecraft.network.packet.Packet14BlockDig.func_73279_a(SourceFile:46)
	at net.minecraft.network.MemoryConnection.func_74428_b(MemoryConnection.java:89)
	at net.minecraft.network.NetServerHandler.func_72570_d(NetServerHandler.java:141)
	at net.minecraft.network.NetworkListenThread.func_71747_b(NetworkListenThread.java:54)
	at net.minecraft.server.integrated.IntegratedServerListenThread.func_71747_b(IntegratedServerListenThread.java:109)
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:691)
	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:587)
	at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:175)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
	at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)