[WARN]: [com.github.retrooper.packetevents.PacketEventsAPI] PacketEvents caught an unhandled exception while calling your listener. java.util.ConcurrentModificationException: null

[Ultim4t]

[03:02:30 WARN]: [com.github.retrooper.packetevents.PacketEventsAPI] PacketEvents caught an unhandled exception while calling your listener.
java.util.ConcurrentModificationException: null
at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1230) ~[?:?]
at PassengerAPI-1.5.1.jar/com.maximde.passengerapi.PassengerManager.addPassengers(PassengerManager.java:117) ~[PassengerAPI-1.5.1.jar:?]
at PassengerAPI-1.5.1.jar/com.maximde.passengerapi.listeners.PacketSendListener.onPacketSend(PacketSendListener.java:36) ~[PassengerAPI-1.5.1.jar:?]
at packetevents-spigot-2.9.4.jar/com.github.retrooper.packetevents.event.PacketListener$1.onPacketSend(PacketListener.java:46) ~[packetevents-spigot-2.9.4.jar:?]
at packetevents-spigot-2.9.4.jar/com.github.retrooper.packetevents.event.PacketSendEvent.call(PacketSendEvent.java:51) ~[packetevents-spigot-2.9.4.jar:?]
at packetevents-spigot-2.9.4.jar/com.github.retrooper.packetevents.event.EventManager.callEvent(EventManager.java:84) ~[packetevents-spigot-2.9.4.jar:?]
at packetevents-spigot-2.9.4.jar/com.github.retrooper.packetevents.util.PacketEventsImplHelper.handleClientBoundPacket(PacketEventsImplHelper.java:61) ~[packetevents-spigot-2.9.4.jar:?]
at packetevents-spigot-2.9.4.jar/io.github.retrooper.packetevents.injector.handlers.PacketEventsEncoder.handleClientBoundPacket(PacketEventsEncoder.java:82) ~[packetevents-spigot-2.9.4.jar:?]
at packetevents-spigot-2.9.4.jar/io.github.retrooper.packetevents.injector.handlers.PacketEventsEncoder.write(PacketEventsEncoder.java:108) ~[packetevents-spigot-2.9.4.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:893) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:113) ~[netty-codec-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:893) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.handler.codec.MessageToMessageEncoder.writeVoidPromise(MessageToMessageEncoder.java:133) ~[netty-codec-4.1.118.Final.jar:4.1.118.Final]
at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:118) ~[netty-codec-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:893) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:120) ~[netty-codec-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:893) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.ChannelOutboundHandlerAdapter.write(ChannelOutboundHandlerAdapter.java:113) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at net.minecraft.network.Connection$2.write(Connection.java:729) ~[purpur-1.21.8.jar:1.21.8-2483-6c88d74]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:893) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.ChannelDuplexHandler.write(ChannelDuplexHandler.java:115) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at CustomNameplates-Bukkit-3.0.31.jar/net.momirealms.customnameplates.bukkit.BukkitNetworkManager$CNChannelHandler.write(BukkitNetworkManager.java:299) ~[CustomNameplates-Bukkit-3.0.31.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:891) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.ChannelDuplexHandler.write(ChannelDuplexHandler.java:115) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at TAB v5.2.5.jar/me.neznamy.tab.shared.features.injection.NettyPipelineInjector$TabChannelDuplexHandler.write(NettyPipelineInjector.java:76) ~[TAB v5.2.5.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:891) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.ChannelDuplexHandler.write(ChannelDuplexHandler.java:115) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at BetterHealthBar-3.9.2.jar/kr.toxicity.healthbar.nms.v1_21_R5.NMSImpl$PlayerInjection.write(NMSImpl.kt:448) ~[BetterHealthBar-3.9.2.jar:?]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:891) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:875) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:984) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:868) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.DefaultChannelPipeline.write(DefaultChannelPipeline.java:964) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.AbstractChannel.write(AbstractChannel.java:300) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at ProtocolLib.jar/com.comphenix.protocol.injector.netty.channel.NettyChannelProxy.write(NettyChannelProxy.java:210) ~[ProtocolLib.jar:?]
at net.minecraft.network.Connection.doSendPacket(Connection.java:497) ~[purpur-1.21.8.jar:1.21.8-2483-6c88d74]
at net.minecraft.network.Connection.lambda$sendPacket$13(Connection.java:477) ~[purpur-1.21.8.jar:1.21.8-2483-6c88d74]
at ProtocolLib.jar/com.comphenix.protocol.injector.netty.channel.NettyChannelInjector.lambda$proxyAction$7(NettyChannelInjector.java:566) ~[ProtocolLib.jar:?]
at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:173) ~[netty-common-4.1.118.Final.jar:4.1.118.Final]
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:166) ~[netty-common-4.1.118.Final.jar:4.1.118.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472) ~[netty-common-4.1.118.Final.jar:4.1.118.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569) ~[netty-transport-4.1.118.Final.jar:4.1.118.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:998) ~[netty-common-4.1.118.Final.jar:4.1.118.Final]
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.118.Final.jar:4.1.118.Final]
at java.base/java.lang.Thread.run(Thread.java:1575) ~[?:?]

[Ultim4t]

The conflict started to arise with the established

DamageIndicator - https://www.spigotmc.org/resources/%E2%98%A0%EF%B8%8Fdamageindicator%E2%98%A0%EF%B8%8F-customisable-damage-indicator-multicolor-support-100-lagless-%E2%9C%A8.92423/