Error

[15:14:23] [Netty Epoll Server IO #0/ERROR]: [SexyMotd] Unhandled exception occured in onPacketSending(PacketEvent) for SexyMotd
java.lang.NoSuchMethodError: org.bukkit.Server.getOnlinePlayers()[Lorg/bukkit/entity/Player;
    at com.qwertyness.sexymotd.Main.onlinePlayers(Main.java:171) ~[sexymotd-1.3.1.jar:?]
    at com.qwertyness.sexymotdengine.util.Util.replaceDynamicCustomVariables(Util.java:121) ~[sexymotd-1.3.1.jar:?]
    at com.qwertyness.sexymotdengine.response.AnimatedText.dynamicBuild(AnimatedText.java:86) ~[sexymotd-1.3.1.jar:?]
    at com.qwertyness.sexymotdengine.util.MotdConstructor.dynamicBuild(MotdConstructor.java:55) ~[sexymotd-1.3.1.jar:?]
    at com.qwertyness.sexymotd.Main$1.onPacketSending(Main.java:92) ~[sexymotd-1.3.1.jar:?]
    at com.comphenix.protocol.injector.SortedPacketListenerList.invokeSendingListener(SortedPacketListenerList.java:195) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketSending(SortedPacketListenerList.java:149) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.PacketFilterManager.handlePacket(PacketFilterManager.java:588) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.PacketFilterManager.invokePacketSending(PacketFilterManager.java:564) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ProtocolInjector.packetQueued(ProtocolInjector.java:338) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ProtocolInjector.onPacketSending(ProtocolInjector.java:298) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ChannelInjector.processSending(ChannelInjector.java:386) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ChannelInjector.encode(ChannelInjector.java:440) [ProtocolLib.jar:4.3.0]
    at com.comphenix.protocol.injector.netty.ChannelInjector$3.encode(ChannelInjector.java:247) [ProtocolLib.jar:4.3.0]
    at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:107) [silnik.jar:git-Paper-1321]
    at com.comphenix.protocol.injector.netty.ChannelInjector$3.write(ChannelInjector.java:253) [ProtocolLib.jar:4.3.0]
    at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:738) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:801) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:831) [silnik.jar:git-Paper-1321]
    at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1041) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:300) [silnik.jar:git-Paper-1321]
    at com.comphenix.protocol.injector.netty.ChannelProxy.writeAndFlush(ChannelProxy.java:327) [ProtocolLib.jar:4.3.0]
    at net.minecraft.server.v1_12_R1.NetworkManager.a(NetworkManager.java:191) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.NetworkManager.sendPacket(NetworkManager.java:147) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.PacketStatusListener.a(PacketStatusListener.java:149) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.PacketStatusInStart.a(SourceFile:23) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.PacketStatusInStart.a(SourceFile:8) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.NetworkManager.a(NetworkManager.java:130) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.NetworkManager.channelRead0(NetworkManager.java:351) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.NetworkManager.channelRead0(NetworkManager.java:31) [silnik.jar:git-Paper-1321]
    at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [silnik.jar:git-Paper-1321]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:288) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [silnik.jar:git-Paper-1321]
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310) [silnik.jar:git-Paper-1321]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:284) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [silnik.jar:git-Paper-1321]
    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:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [silnik.jar:git-Paper-1321]
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310) [silnik.jar:git-Paper-1321]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:284) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [silnik.jar:git-Paper-1321]
    at net.minecraft.server.v1_12_R1.LegacyPingHandler.channelRead(SourceFile:94) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [silnik.jar:git-Paper-1321]
    at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [silnik.jar:git-Paper-1321]
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [silnik.jar:git-Paper-1321]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [silnik.jar:git-Paper-1321]
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935) [silnik.jar:git-Paper-1321]
    at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:800) [silnik.jar:git-Paper-1321]
    at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404) [silnik.jar:git-Paper-1321]
    at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304) [silnik.jar:git-Paper-1321]
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886) [silnik.jar:git-Paper-1321]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_161]
[15:14:23] [Netty Epoll Server IO #0/ERROR]: Parameters: 
  net.minecraft.server.v1_12_R1.PacketStatusOutServerInfo@7bbe75c4[
    b=net.minecraft.server.v1_12_R1.ServerPing@2329a996
  ]