Bukkit

[17:17:42] [Server thread/INFO]: Starting minecraft server version 1.7.2
[17:17:42] [Server thread/INFO]: Loading properties
[17:17:42] [Server thread/INFO]: Default game type: CREATIVE
[17:17:42] [Server thread/INFO]: Generating keypair
[17:17:42] [Server thread/INFO]: Starting Minecraft server on *:125
[17:17:42] [Server thread/INFO]: This server is running CraftBukkit version git-Bukkit-1.7.2-R0.2-b2974jnks (MC: 1.7.2) (Implementing API version 1.7.2-R0.2)
[17:17:42] [Server thread/INFO]: [PermissionsEx] sql backend registered!
[17:17:42] [Server thread/INFO]: [PermissionsEx] file backend registered!
[17:17:42] [Server thread/INFO]: [Nickname] Loading Nickname v0.1.2
[17:17:42] [Server thread/INFO]: [PermissionsEx] Loading PermissionsEx v1.20.4
[17:17:42] [Server thread/INFO]: [PermissionsEx] Initializing file backend
[17:17:42] [Server thread/INFO]: Permissions file successfully reloaded
[17:17:42] [Server thread/INFO]: Preparing level "world.Core"
[17:17:42] [Server thread/INFO]: Preparing start region for level 0 (Seed: 5638703877532516593)
[17:17:42] [Server thread/INFO]: Preparing start region for level 1 (Seed: 5638703877532516593)
[17:17:43] [Server thread/INFO]: Preparing start region for level 2 (Seed: 5638703877532516593)
[17:17:43] [Server thread/INFO]: [Nickname] Enabling Nickname v0.1.2
[17:17:43] [Server thread/INFO]: Nicknames: ENABLED
[17:17:43] [Server thread/INFO]: [PermissionsEx] Enabling PermissionsEx v1.20.4
[17:17:43] [Server thread/INFO]: Server permissions file permissions.yml is empty, ignoring it
[17:17:43] [Server thread/INFO]: Done (1.119s)! For help, type "help" or "?"
[17:17:54] [User Authenticator #1/INFO]: UUID of player Thuzle is 9cc80d36a2494e88b8e85caf91106dcb
[17:17:54] [Server thread/INFO]: Thuzle[/127.0.0.1:63084] logged in with entity id 277 at ([world.Core] 230.38915797934825, 69.0, 216.30383382091986)
[17:17:54] [Server thread/ERROR]: Could not pass event PlayerJoinEvent to Nickname v0.1.2
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427) ~[craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:481) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:466) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.PlayerList.c(PlayerList.java:225) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.PlayerList.a(PlayerList.java:116) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.LoginListener.c(LoginListener.java:78) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.LoginListener.a(LoginListener.java:42) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:149) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
Caused by: java.lang.NullPointerException
    at me.meztech.nickname.Main.onPlayerJoinEvent(Main.java:130) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_45]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_45]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_45]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_45]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425) ~[craftbukkit-1.7.2-R0.2.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
    ... 14 more
[17:17:57] [Server thread/INFO]: Thuzle lost connection: Disconnected
[17:17:57] [Server thread/INFO]: Thuzle left the game.
[17:18:08] [Server thread/INFO]: CONSOLE: Stopping the server..
[17:18:08] [Server thread/INFO]: Stopping server
[17:18:08] [Server thread/INFO]: [PermissionsEx] Disabling PermissionsEx v1.20.4
[17:18:08] [Server thread/INFO]: Permissions file successfully reloaded
[17:18:08] [Server thread/INFO]: [Nickname] Disabling Nickname v0.1.2
[17:18:08] [Server thread/INFO]: Nicknames: DISABLED
[17:18:08] [Server thread/INFO]: Saving players
[17:18:08] [Server thread/INFO]: Saving worlds
[17:18:08] [Server thread/INFO]: Saving chunks for level 'world.Core'/Overworld
[17:18:08] [Server thread/INFO]: Saving chunks for level 'world.Core_nether'/Nether
[17:18:08] [Server thread/INFO]: Saving chunks for level 'world.Core_the_end'/The End
[17:18:08] [Thread-4/INFO]: Stopping server
[17:18:08] [Thread-4/INFO]: Saving players
[17:18:08] [Thread-4/INFO]: Saving worlds
[17:18:08] [Thread-4/INFO]: Saving chunks for level 'world.Core'/Overworld

Could you please give us the steps that would reproduce the problem? Because right now when I load the current version of the plugin it doesn't give me any errors.

I'll try to give as much information as possible. I run a Test server for plugins before going to my live server. The test server is run on Win 8 64 bit with minimal plugins. Every new plugin the server is completely shutdown and restarted. I have both x86 and 64 bit Java installed on the system.

I deleted the server and made a new one with the only plugin being nick.jar and receive the same error. That is an empty server folder except for craftbukkit.jar, run.bat and plugins/nick.jar