[ProtocolLib] INTERNAL ERROR: Cannot load ProtocolLib.
If this problem hasn't already been reported, please open a ticket
at https://github.com/dmulloy2/ProtocolLib/issues with the following data:
Stack Trace:
java.lang.IllegalArgumentException: Unable to find a field that matches {modifiers=[required: 10000, banned: 1000], type={ type input instanceof interface java.util.Map }}
at com.comphenix.protocol.reflect.FuzzyReflection.getField(FuzzyReflection.java:352)
at com.comphenix.protocol.injector.packet.PacketRegistry.createNewRegister(PacketRegistry.java:188)
at com.comphenix.protocol.injector.packet.PacketRegistry.initialize(PacketRegistry.java:292)
at com.comphenix.protocol.injector.packet.PacketRegistry.getClientPacketTypes(PacketRegistry.java:327)
at com.comphenix.protocol.injector.PacketFilterManager.(PacketFilterManager.java:120)
at com.comphenix.protocol.injector.PacketFilterBuilder.build(PacketFilterBuilder.java:121)
at com.comphenix.protocol.ProtocolLib.onLoad(ProtocolLib.java:183)
at org.bukkit.craftbukkit.v1_20_R3.CraftServer.loadPlugins(CraftServer.java:435)
at net.minecraft.server.dedicated.DedicatedServer.e(DedicatedServer.java:219)
at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:1000)
at net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:304)
at java.base/java.lang.Thread.run(Unknown Source)
Dump:
Parameters:
[NULL]
Sender:
com.comphenix.protocol.ProtocolLib@54b57866[
statistics=
packetTask=
tickCounter=0
configExpectedMod=-1
updater=com.comphenix.protocol.updater.SpigotUpdater@50b6cca0
redirectHandler=
scheduler=com.comphenix.protocol.scheduler.DefaultScheduler@2f3ff898
commandProtocol=
commandPacket=
commandFilter=
packetLogging=
skipDisable=false
isEnabled=false
loader=org.bukkit.plugin.java.JavaPluginLoader@29f2277
server=CraftServer{serverName=CraftBukkit,serverVersion=4056-Spigot-e9ec548-176c0ad,minecraftVersion=1.20.4}
file=plugins/ProtocolLib (1).jar
description=org.bukkit.plugin.PluginDescriptionFile@4c650adf
dataFolder=plugins/ProtocolLib
classLoader=org.bukkit.plugin.java.PluginClassLoader@609398db
naggable=true
newConfig=YamlConfiguration[path='', root='YamlConfiguration']
configFile=plugins/ProtocolLib/config.yml
logger=org.bukkit.plugin.PluginLogger@179b0114
]
Version:
ProtocolLib v5.1.0
Java Version:
21.0.1

someone else found a solution, download protocollib via this site, take a look at step one. ''https://itemsadder.devs.beer/first-install''