Bukkit

[SEVERE] Could not pass event PlayerCommandPreprocessEvent to HawkEye
org.bukkit.event.EventException
        at uk.co.oliwali.HawkEye.listeners.HawkEyeListener$1.execute(HawkEyeListener.java:58)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
        at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:872)
        at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:826)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:808)
        at net.minecraftserverhook.NetServerHandlerProxy.a(NetServerHandlerProxy.java:124)
        at net.minecraft.server.Packet3Chat.handle(Packet3Chat.java:44)
        at net.minecraft.server.NetworkManager.b(NetworkManager.java:276)
        at net.minecraft.server.NetServerHandler.d(NetServerHandler.java:109)
        at net.minecraftserverhook.NetServerHandlerProxy.d(NetServerHandlerProxy.java:58)
        at net.minecraft.server.ServerConnection.b(SourceFile:35)
        at net.minecraft.server.DedicatedServerConnection.b(SourceFile:30)
        at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:578)
        at net.minecraft.server.DedicatedServer.q(DedicatedServer.java:213)
        at net.minecraft.server.MinecraftServer.p(MinecraftServer.java:474)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:406)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)
Caused by: java.lang.NullPointerException
        at org.bukkit.craftbukkit.inventory.CraftInventory.getSize(CraftInventory.java:36)
        at org.bukkit.craftbukkit.inventory.CraftInventory.getContents(CraftInventory.java:49)
        at uk.co.oliwali.HawkEye.util.InventoryUtil.getContainerContents(InventoryUtil.java:166)
        at uk.co.oliwali.HawkEye.ContainerAccessManager.checkInventoryClose(ContainerAccessManager.java:40)
        at uk.co.oliwali.HawkEye.listeners.MonitorPlayerListener.onPlayerCommandPreprocess(MonitorPlayerListener.java:48)
        at sun.reflect.GeneratedMethodAccessor370.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at uk.co.oliwali.HawkEye.listeners.HawkEyeListener$1.execute(HawkEyeListener.java:56)
        ... 18 more