Bukkit

What steps will reproduce the problem?
1. Start server
2. 5th player login
3. Error, then after next player login server crashes

What is the expected output? What do you see instead?
No errors or crashes.

What version of the product are you using?
MyWorlds v1.67
Spigot Build #1257

Do you have an error log of what happened?
15.02 00:36:06 [Server] INFO ... 28 more
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:318) ~[spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_40]
15.02 00:36:06 [Server] INFO at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_40]
15.02 00:36:06 [Server] INFO at sun.reflect.GeneratedMethodAccessor864.invoke(Unknown Source) ~[?:?]
15.02 00:36:06 [Server] INFO at com.pauldavdesign.mineauz.minigames.Events.onGMChange(Events.java:511) ~[?:?]
15.02 00:36:06 [Server] INFO Caused by: java.lang.NullPointerException
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:446) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:540) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:273) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:678) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:150) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.LoginListener.a(LoginListener.java:42) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.LoginListener.c(LoginListener.java:87) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.PlayerList.a(PlayerList.java:116) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at net.minecraft.server.v1_7_R1.PlayerList.c(PlayerList.java:225) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:467) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:482) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:318) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_40]
15.02 00:36:06 [Server] INFO at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_40]
15.02 00:36:06 [Server] INFO at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_40]
15.02 00:36:06 [Server] INFO at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_40]
15.02 00:36:06 [Server] INFO at com.bergerkiller.bukkit.mw.MWListener.onPlayerJoin(MWListener.java:74) [MyWorlds-1.67.jar:?]
15.02 00:36:06 [Server] INFO at com.bergerkiller.bukkit.mw.WorldConfig.onPlayerEnter(WorldConfig.java:418) [MyWorlds-1.67.jar:?]
15.02 00:36:06 [Server] INFO at com.bergerkiller.bukkit.mw.WorldConfig.updateGamemode(WorldConfig.java:531) [MyWorlds-1.67.jar:?]
15.02 00:36:06 [Server] INFO at org.bukkit.craftbukkit.v1_7_R1.entity.CraftPlayer.setGameMode(CraftPlayer.java:759) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:467) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:482) [spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30) ~[spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:320) ~[spigot1257.jar:git-Spigot-1257]
15.02 00:36:06 [Server] INFO org.bukkit.event.EventException

Please provide any additional information below.

I also get this while loading my world: [02:49:37] [Server thread/WARN]: java.lang.Exception [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.Chunk.a(Chunk.java:735) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.Chunk.a(Chunk.java:710) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.ChunkRegionLoader.loadEntities(ChunkRegionLoader.java:381) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.ChunkRegionLoader.a(ChunkRegionLoader.java:52) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.ChunkProviderServer.loadChunk(ChunkProviderServer.java:179) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.common.internal.ChunkProviderServerHook.loadChunk(ChunkProviderServerHook.java:61) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:110) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.common.internal.ChunkProviderServerHook.getChunkAt(ChunkProviderServerHook.java:122) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:88) [02:49:37] [Server thread/WARN]: at org.bukkit.craftbukkit.v1_7_R1.CraftServer.createWorld(CraftServer.java:806) [02:49:37] [Server thread/WARN]: at org.bukkit.Bukkit.createWorld(Bukkit.java:228) [02:49:37] [Server thread/WARN]: at org.bukkit.WorldCreator.createWorld(WorldCreator.java:239) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.mw.WorldManager.createWorld(WorldManager.java:412) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.mw.WorldManager.createWorld(WorldManager.java:347) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.mw.WorldManager.getOrCreateWorld(WorldManager.java:328) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.mw.WorldConfig.loadWorld(WorldConfig.java:447) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.mw.WorldConfigStore.init(WorldConfigStore.java:117) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.mw.MyWorlds.enable(MyWorlds.java:162) [02:49:37] [Server thread/WARN]: at com.bergerkiller.bukkit.common.PluginBase.onEnable(PluginBase.java:753) [02:49:37] [Server thread/WARN]: at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:250) [02:49:37] [Server thread/WARN]: at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:350) [02:49:37] [Server thread/WARN]: at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:385) [02:49:37] [Server thread/WARN]: at org.bukkit.craftbukkit.v1_7_R1.CraftServer.loadPlugin(CraftServer.java:304) [02:49:37] [Server thread/WARN]: at org.bukkit.craftbukkit.v1_7_R1.CraftServer.enablePlugins(CraftServer.java:286) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.m(MinecraftServer.java:348) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.g(MinecraftServer.java:325) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.a(MinecraftServer.java:281) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.DedicatedServer.init(DedicatedServer.java:186) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:430) [02:49:37] [Server thread/WARN]: at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617)