Forge v14.23.4.2747-1.12.2
Metamorph v1.1.6

I'm not sure if the cause is from this mod, but I got the following error after killing a chameleon from Primitive Mobs with a plain Minecraft wooden sword, although this has also happened with mobs from other mods as well. I was disconnected before the mob played the death animation and before it dropped the morph. Any help would be appreciated. Thanks.

Full Log
[21:44:54] [Netty Local Client IO #0/ERROR]: NetworkDispatcher exception java.lang.IllegalArgumentException: Payload may not be larger than 32767 bytes at net.minecraft.network.play.client.CPacketCustomPayload.<init>(CPacketCustomPayload.java:28) ~[lh.class:?] at net.minecraftforge.fml.common.network.internal.FMLProxyPacket.toC17Packet(FMLProxyPacket.java:142) ~[FMLProxyPacket.class:?] at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.write(NetworkDispatcher.java:534) ~[NetworkDispatcher.class:?] at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:738) ~[netty-all-4.1.9.Final.jar:4.1.9.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:801) ~[netty-all-4.1.9.Final.jar:4.1.9.Final] at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814) ~[netty-all-4.1.9.Final.jar:4.1.9.Final] at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794) ~[netty-all-4.1.9.Final.jar:4.1.9.Final] at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:831) ~[netty-all-4.1.9.Final.jar:4.1.9.Final] at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1032) ~[netty-all-4.1.9.Final.jar:4.1.9.Final] at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:296) ~[netty-all-4.1.9.Final.jar:4.1.9.Final] at net.minecraft.network.NetworkManager$4.run(NetworkManager.java:245) [gw$4.class:?] at io.netty.channel.DefaultEventLoop.run(DefaultEventLoop.java:54) [netty-all-4.1.9.Final.jar:4.1.9.Final] at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [netty-all-4.1.9.Final.jar:4.1.9.Final] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_51] [21:44:58] [main/INFO]: TAN configuration restored to local values [21:44:58] [main/INFO]: Client fetcher- all player data decached [21:45:10] [Server thread/INFO]: WenXin2 lost connection: Disconnected [21:45:10] [Server thread/INFO]: WenXin2 left the game

Does it kicks you out when you pick up the morph or when you immediately kill it? I'm not sure, but I feel like those mobs have a lot of NBT information stored in them, so this is the issue. Unfortunately, I can do nothing about this issue as it's a limit set by the Forge.

It kicked me immediately after killing it, although it kicked me before the death animation occurred, so I'm assuming that's what happened. It also didn't kick me on the first mob kill, the one that kicked me was the third mob kill. I do have the both Epic Seige and Scaling Health mods installed, could that cause this to happen?

After looking on Chameleon's code in Primitive Mobs' source, it's clearly not the mob itself a source of this issue. I can't really tell what's exactly the issue. Could you try enabling Acquire morph immediately config option and see whether this issue happens again?

But please, back up the world, because I feel like this idea might get your world crashing (i.e. somewhat corrupted).

Ah, I see, thanks for letting me know! 🙂

Ok, I finally figured out what was going on. It's when I have the mod Sword Stat installed and when swinging a sword that I get the error. It looks like it's not from metamorph.