Having an NPC appear when the server is running behind a bungee proxy create an IllegalArgumentException. As the proxy is trying to convert NPC to real player and add a scoreboard objective to it. Tried the same server with Velocity and the bug isn't present.
23:50:59 [SEVERE] [ObsidianSmelter] <-> DownstreamBridge <-> [bedwars] - encountered exception
java.lang.IllegalArgumentException: Team [NPC] d9b8a7935e already exists in this scoreboard
at com.google.common.base.Preconditions.checkArgument(Preconditions.java:220)
at net.md_5.bungee.api.score.Scoreboard.addTeam(Scoreboard.java:73)
at net.md_5.bungee.connection.DownstreamBridge.handle(DownstreamBridge.java:223)
at net.md_5.bungee.protocol.packet.Team.handle(Team.java:124)
at net.md_5.bungee.netty.HandlerBoss.channelRead(HandlerBoss.java:114)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:296)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at java.lang.Thread.run(Thread.java:748)
23:50:59 [INFO] [ObsidianSmelter] disconnected with: §fIllegalArgumentException : Team [NPC] d9b8a7935e already exists in this scoreboard @ com.google.common.base.Preconditions:220
Having an NPC appear when the server is running behind a bungee proxy create an IllegalArgumentException. As the proxy is trying to convert NPC to real player and add a scoreboard objective to it. Tried the same server with Velocity and the bug isn't present.