[17:48:15 ERROR]: Could not pass event PlayerInteractEvent to Lobby vRelease 4.0  org.bukkit.event.EventException         at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja va:320) ~[Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav a:62) ~[Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j ava:486) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j ava:471) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at org.bukkit.craftbukkit.v1_7_R1.event.CraftEventFactory.callPlayerInte ractEvent(CraftEventFactory.java:195) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2 b35-b3019jnks]         at net.minecraft.server.v1_7_R1.PlayerInteractManager.interact(PlayerInt eractManager.java:374) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java :628) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.PacketPlayInBlockPlace.a(SourceFile:60) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.PacketPlayInBlockPlace.handle(SourceFile :9) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146 ) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [Serv er.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:6 55) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:2 50) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:5 45) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java :457) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:6 17) [Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks] Caused by: java.lang.NullPointerException         at Lobby.Main.onSignClick(Main.java:136) ~[?:?]         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0 _67]         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0 _67]         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1 .7.0_67]         at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_67]         at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja va:318) ~[Server.jar:git-Bukkit-1.7.2-R0.2-50-gdce2b35-b3019jnks]         ... 15 more