10:59:30 [WARNING] Failed to handle packet: java.lang.NullPointerException
java.lang.NullPointerException
        at net.minecraft.server.ItemStack.d(ItemStack.java:89)
        at net.minecraft.server.ItemStack.f(ItemStack.java:97)
        at net.minecraft.server.InventoryPlayer.a(InventoryPlayer.java:124)
        at net.minecraft.server.EntityItem.b(EntityItem.java:203)
        at net.minecraft.server.EntityHuman.i(EntityHuman.java:195)
        at net.minecraft.server.EntityHuman.q(EntityHuman.java:187)
        at net.minecraft.server.EntityPlayer.q(EntityPlayer.java:197)
        at net.minecraft.server.EntityLiving.f_(EntityLiving.java:231)
        at net.minecraft.server.EntityHuman.f_(EntityHuman.java:82)
        at net.minecraft.server.EntityPlayer.a(EntityPlayer.java:154)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:222)
        at net.minecraft.server.Packet10Flying.a(SourceFile:126)
        at net.minecraft.server.NetworkManager.a(SourceFile:230)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:76)
        at net.minecraft.server.NetworkListenThread.a(SourceFile:100)
        at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:357)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:272)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:366)