Console kill mobs error

[2robie]

Hello, I have an error that appears in my console when I kill a mob. I'm in 1.20.4 on paper. Here is the error:

[23:37:12 WARN]: java.lang.RuntimeException: no class found: net.minecraft.world.item.component.CustomData
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.EvLib.extras.ReflectionUtils.getRefClass(ReflectionUtils.java:99)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.EvLib.extras.NBTTagUtils.<clinit>(NBTTagUtils.java:39)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.DropHeads.JunkUtils.getDisplayName(JunkUtils.java:185)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.DropHeads.JunkUtils.getMurderItemComponent(JunkUtils.java:326)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.DropHeads.DropChanceAPI.getWeaponComponent(DropChanceAPI.java:573)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.DropHeads.DropChanceAPI.getBeheadMessage(DropChanceAPI.java:591)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.DropHeads.DropChanceAPI.triggerHeadDropEvent(DropChanceAPI.java:742)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.DropHeads.listeners.EntityDeathListener.onEntityDeath(EntityDeathListener.java:158)
[23:37:12 WARN]:        at DropHeads_v3.9.10.jar//net.evmodder.DropHeads.listeners.EntityDeathListener$DeathEventExecutor.execute(EntityDeathListener.java:293)
[23:37:12 WARN]:        at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:81)
[23:37:12 WARN]:        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70)
[23:37:12 WARN]:        at io.papermc.paper.plugin.manager.PaperEventManager.callEvent(PaperEventManager.java:54)
[23:37:12 WARN]:        at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.callEvent(PaperPluginManagerImpl.java:126)
[23:37:12 WARN]:        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:615)
[23:37:12 WARN]:        at org.bukkit.craftbukkit.v1_20_R3.event.CraftEventFactory.callEntityDeathEvent(CraftEventFactory.java:987)
[23:37:12 WARN]:        at net.minecraft.world.entity.EntityLiving.dropAllDeathLoot(EntityLiving.java:1847)
[23:37:12 WARN]:        at net.minecraft.world.entity.EntityLiving.a(EntityLiving.java:1741)
[23:37:12 WARN]:        at net.minecraft.world.entity.EntityLiving.a(EntityLiving.java:1565)
[23:37:12 WARN]:        at net.minecraft.world.entity.animal.EntityAnimal.a(EntityAnimal.java:87)
[23:37:12 WARN]:        at net.minecraft.world.entity.player.EntityHuman.d(EntityHuman.java:1323)
[23:37:12 WARN]:        at net.minecraft.server.level.EntityPlayer.d(EntityPlayer.java:2283)
[23:37:12 WARN]:        at net.minecraft.server.network.PlayerConnection$3.a(PlayerConnection.java:2787)
[23:37:12 WARN]:        at net.minecraft.network.protocol.game.PacketPlayInUseEntity$1.a(PacketPlayInUseEntity.java:24)
[23:37:12 WARN]:        at net.minecraft.network.protocol.game.PacketPlayInUseEntity.a(PacketPlayInUseEntity.java:80)
[23:37:12 WARN]:        at net.minecraft.server.network.PlayerConnection.a(PlayerConnection.java:2711)
[23:37:12 WARN]:        at net.minecraft.network.protocol.game.PacketPlayInUseEntity.a(PacketPlayInUseEntity.java:67)
[23:37:12 WARN]:        at net.minecraft.network.protocol.game.PacketPlayInUseEntity.a(PacketPlayInUseEntity.java:12)
[23:37:12 WARN]:        at net.minecraft.network.protocol.PlayerConnectionUtils.lambda$ensureRunningOnSameThread$0(PlayerConnectionUtils.java:54)
[23:37:12 WARN]:        at net.minecraft.server.TickTask.run(TickTask.java:18)
[23:37:12 WARN]:        at net.minecraft.util.thread.IAsyncTaskHandler.d(IAsyncTaskHandler.java:149)
[23:37:12 WARN]:        at net.minecraft.util.thread.IAsyncTaskHandlerReentrant.d(IAsyncTaskHandlerReentrant.java:24)
[23:37:12 WARN]:        at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1465)
[23:37:12 WARN]:        at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:194)
[23:37:12 WARN]:        at net.minecraft.util.thread.IAsyncTaskHandler.x(IAsyncTaskHandler.java:123)
[23:37:12 WARN]:        at net.minecraft.server.MinecraftServer.bl(MinecraftServer.java:1442)
[23:37:12 WARN]:        at net.minecraft.server.MinecraftServer.x(MinecraftServer.java:1365)
[23:37:12 WARN]:        at net.minecraft.util.thread.IAsyncTaskHandler.bu(IAsyncTaskHandler.java:112)
[23:37:12 WARN]:        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:1557)
[23:37:12 WARN]:        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:1226)
[23:37:12 WARN]:        at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:319)
[23:37:12 WARN]:        at java.base/java.lang.Thread.run(Thread.java:1583)
[23:37:12 WARN]: 
[23:37:12 WARN]: Found inconsistent skull meta, this should normally not happen and is not a Bukkit / Spigot issue, but one from a plugin you are using.
Bukkit will attempt to fix it this time for you, but may not be able to do this every time.
If you see this message after typing a command from a plugin, please report this to the plugin developer, they should use the api instead of relying on reflection (and doing it the wrong way).
[23:37:12 WARN]: Found inconsistent skull meta, this should normally not happen and is not a Bukkit / Spigot issue, but one from a plugin you are using.
Bukkit will attempt to fix it this time for you, but may not be able to do this every time.
If you see this message after typing a command from a plugin, please report this to the plugin developer, they should use the api instead of relying on reflection (and doing it the wrong way).

[EvModder]

Hmm, I probably broke something related to 1.20.4 when adding support for 1.21.4
I should be able to fix this pretty quickly (sorry for the slow reply on the bug report), but I recommend downgrading to a previous version of DropHeads in the meantime if you need to get it working

[2robie]

Hello, sorry I didn't see your message earlier, where can I find the old versions?

[EvModder]

Try v3.9.9 from here:
https://dev.bukkit.org/projects/dropheads/files

[2robie]

Hello, I put your version but I still have Warn messages in the console, I tried to take an even older version like DropHeads v3.9.3 but it's the same.

[EvModder]

Hmm, I don't remember which version was working for Minecraft 1.20.4 in that case... I'll need to fix that for backwards support for older servers, sorry it's taking me a while to get it fixed, 1.20.4 was weird in-between version, Mojang was still deciding how they wanted to implement component API and did things differently in that one version.

Fingers crossed, but I can probably get around to doing it this weekend

[2robie]

Alright thanks, good luck :)