PfluorescentZebra

This is also happening to my husband and myself; we can play for some time (roughly 4 hours) and then it will kick whoever is not hosting the game. The full stacktrace: [Netty Server IO #3/ERROR]: Error encoding packet io.netty.util.IllegalReferenceCountException: refCnt: 0 at io.netty.buffer.AbstractByteBuf.ensureAccessible(AbstractByteBuf.java:1454) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.buffer.AbstractByteBuf.checkIndex(AbstractByteBuf.java:1383) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.buffer.UnpooledHeapByteBuf.copy(UnpooledHeapByteBuf.java:534) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.buffer.AbstractByteBuf.copy(AbstractByteBuf.java:1194) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at net.minecraft.network.FriendlyByteBuf.copy(FriendlyByteBuf.java:1169) ~[client-1.18.1-20211210.034407-srg.jar%23142!:?] at net.minecraft.network.protocol.game.ClientboundCustomPayloadPacket.m_5779_(ClientboundCustomPayloadPacket.java:50) ~[client-1.18.1-20211210.034407-srg.jar%23142!:?] at net.minecraft.network.PacketEncoder.encode(PacketEncoder.java:42) ~[client-1.18.1-20211210.034407-srg.jar%23142!:?] at net.minecraft.network.PacketEncoder.encode(PacketEncoder.java:15) ~[client-1.18.1-20211210.034407-srg.jar%23142!:?] at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:107) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:110) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:764) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:790) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:758) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:808) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1025) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:306) ~[netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at net.minecraft.network.Connection.m_178303_(Connection.java:202) ~[client-1.18.1-20211210.034407-srg.jar%23142!:?] at net.minecraft.network.Connection.lambda$sendPacket$5(Connection.java:191) ~[client-1.18.1-20211210.034407-srg.jar%23142!:?] at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164) [netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:469) [netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:500) [netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986) [netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) [netty-all-4.1.68.Final.jar%2332!:4.1.68.Final] at java.lang.Thread.run(Thread.java:833) [?:?] Nothing is mentioning a specific mod, all seem to be referencing normal java classes and I cannot see what specifically it is encoding. We removed his player profile completely (deleted the UUID files in playerdata folder) and the problem persisted. Each player restarted the session, then the game, then the computer. Both players can use the same save on singleplayer, issue only occurs when using LAN. No issues with internet connectivity or local interference. No issues with previous versions of Minecraft using LAN. Will be glad to offer additional information if necessary.