[21:14:02] [Netty Epoll Server IO #3/ERROR]: [PAC] Unhandled exception occured in onPacketReceiving(PacketEvent) for PAC
java.util.ConcurrentModificationException
    at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901) ~[?:1.8.0_91]
    at java.util.ArrayList$Itr.next(ArrayList.java:851) ~[?:1.8.0_91]
    at npnp.cU.a(cU.java:83) ~[PAC.jar:?]
    at npnp.bB.b(bB.java:56) ~[PAC.jar:?]
    at npnp.ah.onPacketReceiving(ah.java:44) ~[PAC.jar:?]
    at com.comphenix.protocol.injector.SortedPacketListenerList.invokeReceivingListener(SortedPacketListenerList.java:114) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketRecieving(SortedPacketListenerList.java:67) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.PacketFilterManager.handlePacket(PacketFilterManager.java:590) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.PacketFilterManager.invokePacketRecieving(PacketFilterManager.java:557) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ProtocolInjector.packetReceived(ProtocolInjector.java:352) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ProtocolInjector.onPacketReceiving(ProtocolInjector.java:317) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ChannelInjector.decode(ChannelInjector.java:531) [ProtocolLib.jar:4.3.0]
    at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:249) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:149) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319) [paper.jar:git-PaperSpigot-"8b18730"]
    at com.comphenix.protocol.injector.netty.ChannelInjector$4.channelRead(ChannelInjector.java:263) [ProtocolLib.jar:4.3.0]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.handler.timeout.ReadTimeoutHandler.channelRead(ReadTimeoutHandler.java:150) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:319) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:787) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.epoll.EpollSocketChannel$EpollSocketUnsafe.epollInReady(EpollSocketChannel.java:722) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:326) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:264) [paper.jar:git-PaperSpigot-"8b18730"]
    at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116) [paper.jar:git-PaperSpigot-"8b18730"]
    at java.lang.Thread.run(Thread.java:745) [?:1.8.0_91]
[21:14:02] [Netty Epoll Server IO #3/ERROR]: Parameters:
  net.minecraft.server.v1_8_R3.PacketPlayInUseEntity@1d490b89[
    a=2659
    action=ATTACK
    c=<null>
  ]