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:183)
at com.comphenix.protocol.injector.packet.PacketRegistry.initialize(PacketRegistry.java:334)
at com.comphenix.protocol.injector.packet.PacketRegistry.getClientPacketTypes(PacketRegistry.java:369)
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_R4.CraftServer.loadPlugins(CraftServer.java:435)
at net.minecraft.server.dedicated.DedicatedServer.e(DedicatedServer.java:232)
at net.minecraft.server.MinecraftServer.y(MinecraftServer.java:1010)
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:311)
at java.base/java.lang.Thread.run(Unknown Source)
Dump:
Parameters:
[NULL]
Sender:
com.comphenix.protocol.ProtocolLib@2f2bb265[
statistics=
packetTask=
tickCounter=0
configExpectedMod=-1
updater=com.comphenix.protocol.updater.SpigotUpdater@475d811a
redirectHandler=
scheduler=com.comphenix.protocol.scheduler.DefaultScheduler@3597ab0e
commandProtocol=
commandPacket=
commandFilter=
packetLogging=
skipDisable=false
isEnabled=false
loader=org.bukkit.plugin.java.JavaPluginLoader@1ada154
server=CraftServer{serverName=CraftBukkit,serverVersion=4149-Spigot-e2c1eee-4e7d749,minecraftVersion=1.20.6}
file=plugins\ProtocolLib.jar
description=org.bukkit.plugin.PluginDescriptionFile@5aeae0d5
dataFolder=plugins\ProtocolLib
classLoader=org.bukkit.plugin.java.PluginClassLoader@558bef20
naggable=true
newConfig=YamlConfiguration[path='', root='YamlConfiguration']
configFile=plugins\ProtocolLib\config.yml
logger=org.bukkit.plugin.PluginLogger@51f0f621
]
Version:
ProtocolLib v5.2.0-SNAPSHOT-679
Java Version:
21.0.3
Server:
4149-Spigot-e2c1eee-4e7d749 (MC: 1.20.6)

Should be fixed in the latest dev build so please use the latest dev build and try again: https://ci.dmulloy2.net/job/ProtocolLib/lastSuccessfulBuild/