Excepción del decodificador al intentar teleportar al jugador.

Creé un complemento PvP para el servidor de Minecraft, pero cuando presiono teleportar al mundo, obtengo un error:

Excepción interna: io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndex(47) + lenght(1) excede el writerIndex(47): UnpooledHeapByteBuf(ridx: 47, widx: 47, cap: 47)

Ya revisé el código y no hay errores. Este es mi código:

Location playerSpawn = new Location(map_world, spawn1x + moves * 200, (double)spawn1y, (double)spawn1z, (float) spawnYaw, (float) spawnPitch);
player.teleport(playerSpawn);

// luego envío un NPC al jugador
EntityPlayer npc = new EntityPlayer(server, world, profile, new PlayerInteractManager(world));
npc.setLocation(npcX + moves * 200, npcY, npcZ, 0.0f, 90.0f);
CraftLivingEntity cle = (CraftLivingEntity) npc.getBukkitEntity();
ItemStack itemstack = ItemUtils.getItem(Material.STICK, 1, Enchantment.KNOCKBACK);
cle.getEquipment().setItemInHand(itemstack);
EntityPlayer ep = ((CraftPlayer) p).getHandle();
PlayerConnection connection = ep.playerConnection;
connection.sendPacket(new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.ADD_PLAYER, npc));
connection.sendPacket(new PacketPlayOutNamedEntitySpawn(npc));
connection.sendPacket(new PacketPlayOutEntityEquipment(npc.getBukkitEntity().getEntityId(), 0, CraftItemStack.asNMSCopy(itemstack)));
DataWatcher watcher = npc.getDataWatcher();
watcher.watch(10, 127);
PacketPlayOutEntityMetadata packet = new PacketPlayOutEntityMetadata(npc.getId(), watcher, false);
connection.sendPacket(packet4);

¿Qué puede estar causando este error?