Stack Trace:
java.lang.IllegalArgumentException: Unable to find a field null with the type com.mojang.authlib.GameProfile in net.minecraft.network.protocol.login.PacketLoginInStart
at ProtocolLib.jar//com.comphenix.protocol.reflect.FuzzyReflection.getFieldByType(FuzzyReflection.java:397)
at ProtocolLib.jar//com.comphenix.protocol.reflect.accessors.Accessors.getFieldAccessor(Accessors.java:57)
at ProtocolLib.jar//com.comphenix.protocol.injector.netty.ChannelInjector.handleLogin(ChannelInjector.java:651)
at ProtocolLib.jar//com.comphenix.protocol.injector.netty.ChannelInjector.decode(ChannelInjector.java:584)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:529)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:468)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at ProtocolLib.jar//com.comphenix.protocol.injector.netty.ChannelInjector$2.channelRead(ChannelInjector.java:289)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.handler.flush.FlushConsolidationHandler.channelRead(FlushConsolidationHandler.java:152)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:800)
at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:499)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:397)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at java.base/java.lang.Thread.run(Thread.java:833)
Dump:
Parameters:
io.netty.buffer.PooledUnsafeDirectByteBuf@5f81c5eb[
memoryAddress=139632809853840
recyclerHandle=io.netty.util.Recycler$DefaultHandle@518f5234
chunk=Chunk(3ee0d87f: 23%, 958464/4194304)
handle=20829212701097985
memory=java.nio.DirectByteBuffer[pos=0 lim=4194304 cap=4194304]
offset=303152
length=34
maxLength=48
cache=io.netty.buffer.PoolThreadCache@50a6ef96
tmpNioBuf=
allocator=PooledByteBufAllocator(directByDefault: true)
refCnt=2
readerIndex=34
writerIndex=34
markedReaderIndex=0
markedWriterIndex=0
maxCapacity=2147483647
]
manager:
com.comphenix.protocol.injector.PacketFilterManager@4986cbac[
unhookTask=com.comphenix.protocol.injector.DelayedSingleTask@44220298
packetListeners=[]
packetInjector=com.comphenix.protocol.injector.netty.ProtocolInjector$5@5047f9a7
playerInjection=com.comphenix.protocol.injector.netty.ProtocolInjector$4@24d5ce56
inputBufferedPackets=[]
recievedListeners=com.comphenix.protocol.injector.SortedPacketListenerList@5b71aacb
sendingListeners=com.comphenix.protocol.injector.SortedPacketListenerList@f1345ff
hasClosed=false
classLoader=PluginClassLoader{plugin=ProtocolLib v4.7.1-SNAPSHOT-b533, pluginEnabled=true, url=plugins/ProtocolLib.jar}
reporter=com.comphenix.protocol.ProtocolLib$1@6a5bda4d
server=CraftServer{serverName=Paper,serverVersion=git-Paper-119,minecraftVersion=1.20.1}
library=ProtocolLib v4.7.1-SNAPSHOT-b533
asyncFilterManager=com.comphenix.protocol.async.AsyncFilterManager@290384f8
knowsServerPackets=true
knowsClientPackets=true
phaseLoginCount=0
phasePlayingCount=0
packetCreation=false
nettyInjector=com.comphenix.protocol.injector.netty.ProtocolInjector@14255353
pluginVerifier=com.comphenix.protocol.injector.PluginVerifier@1fabbfc8
hasRecycleDistance=true
minecraftVersion=(MC: 1.20.1)
debug=false
]
Sender:
com.comphenix.protocol.injector.netty.ChannelInjector@49634d72[
decodeBuffer=protected void net.minecraft.network.PacketDecoder.decode(io.netty.channel.ChannelHandlerContext,io.netty.buffer.ByteBuf,java.util.List) throws java.lang.Exception
encodeBuffer=protected void net.minecraft.network.PacketEncoder.encode(io.netty.channel.ChannelHandlerContext,java.lang.Object,io.netty.buffer.ByteBuf) throws java.lang.Exception
factory=com.comphenix.protocol.injector.netty.InjectionFactory@357f7817
player=CraftPlayer{name=twig46}
updated=
playerName=twig46
playerConnection=
networkManager=net.minecraft.network.NetworkManager@62c2b4da
originalChannel=[id: 0xceb44be9, L:/240.8.6.34:25575 - R:/240.8.65.106:40814]
channelField=VolatileField [accessor=DefaultFieldAccessor [field=public io.netty.channel.Channel net.minecraft.network.NetworkManager.m], container=net.minecraft.network.NetworkManager@62c2b4da, previous=[id: 0xceb44be9, L:/240.8.6.34:25575 - R:/240.8.65.106:40814], current=com.comphenix.protocol.injector.netty.ChannelInjector$3@1671319b, previousLoaded=true, currentSet=true, forceAccess=true]
packetMarker={}
currentEvent=
finalEvent=
unfilteredProcessedPackets=com.comphenix.protocol.injector.netty.PacketFilterQueue@39e751f
vanillaDecoder=net.minecraft.network.PacketDecoder@1cfc711e
vanillaEncoder=net.minecraft.network.PacketEncoder@3b911e5e
finishQueue=[]
channelListener=com.comphenix.protocol.injector.netty.ProtocolInjector@14255353
processor=com.comphenix.protocol.injector.NetworkProcessor@5c5609b7
injected=true
closed=false
cumulation=PooledUnsafeDirectByteBuf(ridx: 34, widx: 34, cap: 34)
cumulator=io.netty.handler.codec.ByteToMessageDecoder$1@23ddf7a2
singleDecode=false
first=true
firedChannelRead=false
selfFiredChannelRead=true
decodeState=1
discardAfterReads=16
numReads=0
added=true
]
Version:
ProtocolLib v4.7.1-SNAPSHOT-b533
Java Version:
17.0.7
Server:
git-Paper-119 (MC: 1.20.1)
save-off

ProtocolLib 4.7.1 is really old and does not support Minecraft 1.20.1. Please use the latest release of ProtocolLib: https://github.com/dmulloy2/ProtocolLib/releases/download/5.1.0/ProtocolLib.jar.