java.lang.IllegalArgumentException: Cannot request protocol 99

[AfkF24]

I am basically getting my console spammed with this. Server is completely timed out while this is happening.

[20:01:58] [Netty Worker IO Thread #2/ERROR]: [/X.X.X.X:46611] <-> InitialHandler - encountered exception
java.lang.IllegalArgumentException: Cannot request protocol 99
	at net.md_5.bungee.connection.InitialHandler.handle(InitialHandler.java:354) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at net.md_5.bungee.protocol.packet.Handshake.handle(Handshake.java:44) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at net.md_5.bungee.netty.HandlerBoss.channelRead(HandlerBoss.java:105) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:321) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:308) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:422) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.handlerRemoved(ByteToMessageDecoder.java:253) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:505) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:437) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:792) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:475) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[waterfall-319.jar:git:Waterfall-Bootstrap:1.15-SNAPSHOT:ea7863f:319]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_242]

[Leymooo]

SpigotMC/BungeeCord#2793

I think this is a main cause why all this "exploits" work and actually can drop bungeecord

[electronicboy]

many issues like this have been severely neutered over the past god knows how long