[WARNING] Failed to handle packet. Bukkit #1559

My server is lagged, unplayable. Im using Bukkit #1559. Any ideas? I have this error in the log:

Code:

[WARNING] Failed to handle packet: java.lang.ArrayIndexOutOfBoundsExcep
tion: -1
java.lang.ArrayIndexOutOfBoundsException: -1
        at java.util.ArrayList.fastRemove(ArrayList.java:441)
        at java.util.ArrayList.remove(ArrayList.java:424)
        at net.minecraft.server.PlayerInstance.b(PlayerInstance.java:51)
        at net.minecraft.server.PlayerManager.removePlayer(PlayerManager.java:10
9)
        at net.minecraft.server.ServerConfigurationManager.disconnect(ServerConf
igurationManager.java:159)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:650)
        at lishid.orebfuscator.utils.NetServerHandlerProxy.a(NetServerHandlerPro
xy.java:85)
        at net.minecraft.server.NetworkManager.b(NetworkManager.java:231)
        at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:46)
        at net.minecraft.server.NetworkListenThread.a(SourceFile:94)
        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:516)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:414)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)

 

Try an older, more stable dev build.