When I open and join my server, it shows these:
[14:55:07 ERROR]: [ProtocolLib] INTERNAL ERROR: Cannot compile structure. Disabing compiler.
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.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @16b15fc0
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:357)
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199)
at java.base/java.lang.reflect.Method.setAccessible(Method.java:193)
at com.comphenix.protocol.reflect.compiler.StructureCompiler.generateClass(StructureCompiler.java:299)
at com.comphenix.protocol.reflect.compiler.StructureCompiler.compile(StructureCompiler.java:213)
at com.comphenix.protocol.reflect.compiler.BackgroundCompiler$2.call(BackgroundCompiler.java:204)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at java.base/java.lang.Thread.run(Thread.java:831)
Dump:
Parameters:
com.comphenix.protocol.reflect.StructureModifier@7a521aa[
targetType=class net.minecraft.server.v1_16_R3.PacketPlayInFlying$PacketPlayInPositionLook
target=
converter=
fieldType=class java.lang.Object
data=[public double net.minecraft.server.v1_16_R3.PacketPlayInFlying.x, public double net.minecraft.server.v1_16_R3.PacketPlayInFlying.y, public double net.minecraft.server.v1_16_R3.PacketPlayInFlying.z, public float net.minecraft.server.v1_16_R3.PacketPlayInFlying.yaw, public float net.minecraft.server.v1_16_R3.PacketPlayInFlying.pitch, protected boolean net.minecraft.server.v1_16_R3.PacketPlayInFlying.f, public boolean net.minecraft.server.v1_16_R3.PacketPlayInFlying.hasPos, public boolean net.minecraft.server.v1_16_R3.PacketPlayInFlying.hasLook]
defaultFields={}
subtypeCache={}
customConvertHandling=false
useStructureCompiler=true
]
manager:
com.comphenix.protocol.injector.PacketFilterManager@4c555b56[
unhookTask=com.comphenix.protocol.injector.DelayedSingleTask@4acf07ce
packetListeners=[PacketAdapter[plugin=AntiCheatReloaded, sending=EMPTY_WHITELIST, receiving=ListeningWhitelist[priority=LOWEST, packets=[BLOCK_DIG[class=PacketPlayInBlockDig, id=27]], gamephase=PLAYING, options=[]]], PacketAdapter[plugin=AuthMe, sending=ListeningWhitelist[priority=NORMAL, packets=[WINDOW_ITEMS[class=PacketPlayOutWindowItems, id=19], SET_SLOT[class=PacketPlayOutSetSlot, id=21]], gamephase=PLAYING, options=[]], receiving=EMPTY_WHITELIST], PacketAdapter[plugin=AntiCheatReloaded, sending=ListeningWhitelist[priority=LOWEST, packets=[KEEP_ALIVE[class=PacketPlayOutKeepAlive, id=31], KEEP_ALIVE[class=PacketPlayInKeepAlive, id=16]], gamephase=PLAYING, options=[]], receiving=ListeningWhitelist[priority=LOWEST, packets=[KEEP_ALIVE[class=PacketPlayOutKeepAlive, id=31], KEEP_ALIVE[class=PacketPlayInKeepAlive, id=16]], gamephase=PLAYING, options=[]]], PacketAdapter[plugin=AntiCheatReloaded, sending=ListeningWhitelist[priority=LOWEST, packets=[POSITION[class=PacketPlayOutPosition, id=52], POSITION[class=PacketPlayInPosition, id=18], POSITION_LOOK[class=PacketPlayInPositionLook, id=19]], gamephase=PLAYING, options=[]], receiving=ListeningWhitelist[priority=LOWEST, packets=[POSITION[class=PacketPlayOutPosition, id=52], POSITION[class=PacketPlayInPosition, id=18], POSITION_LOOK[class=PacketPlayInPositionLook, id=19]], gamephase=PLAYING, options=[]]]]
packetInjector=com.comphenix.protocol.injector.netty.ProtocolInjector$5@5e9a4758
playerInjection=com.comphenix.protocol.injector.netty.ProtocolInjector$4@701c9550
inputBufferedPackets=[]
recievedListeners=com.comphenix.protocol.injector.SortedPacketListenerList@16f5ffee
sendingListeners=com.comphenix.protocol.injector.SortedPacketListenerList@24b67b89
hasClosed=false
classLoader=PluginClassLoader{plugin=ProtocolLib v4.6.0, pluginEnabled=true, url=plugins\ProtocolLib.jar}
reporter=com.comphenix.protocol.ProtocolLib$1@289a48c0
server=CraftServer{serverName=Paper,serverVersion=git-Paper-670,minecraftVersion=1.16.5}
library=ProtocolLib v4.6.0
asyncFilterManager=com.comphenix.protocol.async.AsyncFilterManager@50b7c60
knowsServerPackets=true
knowsClientPackets=true
phaseLoginCount=0
phasePlayingCount=6
packetCreation=false
nettyInjector=com.comphenix.protocol.injector.netty.ProtocolInjector@4d51ba1f
pluginVerifier=com.comphenix.protocol.injector.PluginVerifier@6eaf0333
hasRecycleDistance=true
minecraftVersion=(MC: 1.16.5)
debug=false
]
Sender:
com.comphenix.protocol.reflect.compiler.BackgroundCompiler@30f9800[
listeners={com.comphenix.protocol.reflect.compiler.StructureCompiler$StructureKey@642e5143=[com.comphenix.protocol.injector.StructureCache$1@29a158da]}
listenerLock=java.lang.Object@69608eb3
compiler=com.comphenix.protocol.reflect.compiler.StructureCompiler@7fc0be37
enabled=false
shuttingDown=false
executor=java.util.concurrent.Executors$FinalizableDelegatedExecutorService@70f657
reporter=com.comphenix.protocol.ProtocolLib$1@289a48c0
unknownPermGenBean=java.lang.Object@23b4090b
permGenBean=
disablePermGenFraction=0.65
]
Version:
ProtocolLib v4.6.0
Java Version:
16.0.1
Server:
git-Paper-670 (MC: 1.16.5)

Screenshots

Version Info
https://pastebin.com/raw/iuV7dfJy

My plugins:
AdvancedBan, AntiCheatReloaded, AureliumSkills, AuthMe, BedRegen, ClearLag, CSM, CustomWings, DefensiveTurrets, DeluxeHub, DiscordSRV, DualWield*, EconomyShopGUI, Essentials, EssentialsAntiBuild, EssentialsChat, EssentialsProtect, EssentialsSpawn, GriefPrevention, GroupManager, IPortal, Multiverse-Core, Multiverse-Inventories, ProtocolLib, ReviveMe, SecurityCams, SkQuery, Skript, SmoothTimber, StaffPlus, TAB, TigerReports, UltraCosmetics, Vault, WorldEdit

Duplicate of #1164

This issue is resolved in dev-build 499+.

ty!