The new 1.21.7 version is having issues with the CustomPlayerModels-Bukkit v0.6.22a.

Server Version: Paper 1.21.7 Build 17
Server Plugin Version: Bukkit v0.6.22a
Client Version: Fabric-1.21.7-0.6.22a

When a player joins the server, the following Stack Trace is printed in the server console:

java.lang.NoSuchMethodException: org.bukkit.craftbukkit.entity.CraftPlayer.addChannel(java.lang.String)
at java.base/java.lang.Class.getDeclaredMethod(Class.java:2848)
at io.papermc.reflectionrewriter.runtime.AbstractDefaultRulesReflectionProxy.getDeclaredMethod(AbstractDefaultRulesReflectionProxy.java:95)
at io.papermc.paper.pluginremap.reflect.PaperReflectionHolder.getDeclaredMethod(Unknown Source)
at CustomPlayerModels-Bukkit-0.6.22a.jar//com.tom.cpm.bukkit.Network.onPlayerJoin(Network.java:114)
at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:80)
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:71)
at io.papermc.paper.plugin.manager.PaperEventManager.callEvent(PaperEventManager.java:54)
at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.callEvent(PaperPluginManagerImpl.java:131)
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:628)
at net.minecraft.server.players.PlayerList.placeNewPlayer(PlayerList.java:332)
at net.minecraft.server.network.ServerConfigurationPacketListenerImpl.handleConfigurationFinished(ServerConfigurationPacketListenerImpl.java:184)
at net.minecraft.network.protocol.configuration.ServerboundFinishConfigurationPacket.handle(ServerboundFinishConfigurationPacket.java:22)
at net.minecraft.network.protocol.configuration.ServerboundFinishConfigurationPacket.handle(ServerboundFinishConfigurationPacket.java:8)
at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24)
at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1449)
at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24)
at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1449)
at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:176)
at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:129)
at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1429)
at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1423)
at net.minecraft.util.thread.BlockableEventLoop.managedBlock(BlockableEventLoop.java:139)
at net.minecraft.server.MinecraftServer.managedBlock(MinecraftServer.java:1380)
at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:1388)
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1265)
at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:310)
at java.base/java.lang.Thread.run(Thread.java:1583)

There is no extra logs or errors on client side.

up

I can also note that the Leaf core, Paper fork, has a similar problem, it is also impossible to change or install models, in fact, the plugin does not work.

#809 should fix this