6:09:28 PM [severe]  Could not pass event CreatureSpawnEvent to ExtraHardMode v2.5.1
6:09:28 PM [javastacktrace] 	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:393)
6:09:28 PM [javastacktrace] 	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
6:09:28 PM [javastacktrace] 	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
6:09:28 PM [javastacktrace] 	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
6:09:28 PM [javastacktrace] 	at org.bukkit.craftbukkit.v1_4_R1.event.CraftEventFactory.callCreatureSpawnEvent(CraftEventFactory.java:243)
6:09:28 PM [javastacktrace] 	at yc.addEntity(World.java:1774)
6:09:28 PM [javastacktrace] 	at yc.d(World.java:1737)
6:09:28 PM [javastacktrace] 	at drzhark.customspawner.CustomSpawner.doCustomSpawning(CustomSpawner.java:404)
6:09:28 PM [javastacktrace] 	at drzhark.mocreatures.MoCServerTickHandler.onTickInGame(MoCServerTickHandler.java:29)
6:09:28 PM [javastacktrace] 	at drzhark.mocreatures.MoCServerTickHandler.tickEnd(MoCServerTickHandler.java:95)
6:09:28 PM [javastacktrace] 	at cpw.mods.fml.common.SingleIntervalHandler.tickEnd(SingleIntervalHandler.java:22)
6:09:28 PM [javastacktrace] 	at cpw.mods.fml.common.FMLCommonHandler.tickEnd(FMLCommonHandler.java:138)
6:09:28 PM [javastacktrace] 	at cpw.mods.fml.common.FMLCommonHandler.onPostServerTick(FMLCommonHandler.java:274)
6:09:28 PM [javastacktrace] 	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:828)
6:09:28 PM [javastacktrace] 	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:680)
6:09:28 PM [javastacktrace] 	at fy.run(ThreadMinecraftServer.java:16)
6:09:28 PM [javastacktrace] Caused by: java.lang.IllegalArgumentException: Location or entity class cannot be null
6:09:28 PM [javastacktrace] 	at org.bukkit.craftbukkit.v1_4_R1.CraftWorld.spawn(CraftWorld.java:890)
6:09:28 PM [javastacktrace] 	at org.bukkit.craftbukkit.v1_4_R1.CraftWorld.spawn(CraftWorld.java:864)
6:09:28 PM [javastacktrace] 	at org.bukkit.craftbukkit.v1_4_R1.CraftWorld.spawnEntity(CraftWorld.java:411)
6:09:28 PM [javastacktrace] 	at me.ryanhamshire.ExtraHardMode.EntityEventHandler.onEntitySpawn(EntityEventHandler.java:482)
6:09:28 PM [javastacktrace] 	at sun.reflect.GeneratedMethodAccessor32.invoke(Unknown Source)
6:09:28 PM [javastacktrace] 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
6:09:28 PM [javastacktrace] 	at java.lang.reflect.Method.invoke(Unknown Source)
6:09:28 PM [javastacktrace] 	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:391)