[19:55:33] [Server thread/ERROR]: [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_R2.CraftServer.loadPlugins(CraftServer.java:442)
at net.minecraft.server.dedicated.DedicatedServer.e(DedicatedServer.java:219)
at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:954)
at net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:298)
at java.base/java.lang.Thread.run(Thread.java:833)
Dump:
Parameters:
[NULL]
Sender:
com.comphenix.protocol.ProtocolLib@7ebedfd4[
statistics=
packetTask=
tickCounter=0
configExpectedMod=-1
updater=com.comphenix.protocol.updater.SpigotUpdater@3d8895d7
redirectHandler=
scheduler=com.comphenix.protocol.scheduler.DefaultScheduler@35c0adcd
commandProtocol=
commandPacket=
commandFilter=
packetLogging=
skipDisable=false
isEnabled=false
loader=org.bukkit.plugin.java.JavaPluginLoader@3f8da056
server=CraftServer{serverName=CraftBukkit,serverVersion=3945-Spigot-b60a866-0478e04,minecraftVersion=1.20.2}
file=plugins/ProtocolLib.jar
description=org.bukkit.plugin.PluginDescriptionFile@3e641060
dataFolder=plugins/ProtocolLib
classLoader=org.bukkit.plugin.java.PluginClassLoader@a208be4
naggable=true
newConfig=YamlConfiguration[path='', root='YamlConfiguration']
configFile=plugins/ProtocolLib/config.yml
logger=org.bukkit.plugin.PluginLogger@1e5ddca7
]
Version:
ProtocolLib v5.1.0
Java Version:
18.0.2.1
Server:
3945-Spigot-b60a866-0478e04 (MC: 1.20.2)

Installed Plugins: Plugins (18): LuckPerms, SpigotPing, UltimateTimber, Vault, ProtocolLib, dynmap, WorldEdit, TCPShield, DecentHolograms, Essentials, EssentialsChat, EssentialsSpawn, WorldGuard, CoreProtect, EssentialsProtect, VillagerMarket, Dynmap-WorldGuard, LWC

I just started the server and the above error showed up. Thanks in advance! :)

Ill test it. Thank you :)

Your going to want a dev build from https://ci.dmulloy2.net/job/ProtocolLib/ since 1.20.2 isn't supported in v5.1.0 from what I can tell. (Was released before 1.20.2 came out.)

https://ci.dmulloy2.net/job/ProtocolLib/673/ is the latest dev build.