[16:13:59 ERROR]: Could not pass event PlayerChangedWorldEvent to PerWorldWelcome v1.2
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.PlayerList.moveToWorld(PlayerList.java:628) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.entity.CraftPlayer.teleport(CraftPlayer.java:471) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.entity.CraftEntity.teleport(CraftEntity.java:226) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at com.onarandombox.MultiverseCore.utils.SimpleSafeTTeleporter.safelyTeleport(SimpleSafeTTeleporter.java:215) [Multiverse-Core-2.5-b717.jar:?]
        at com.onarandombox.MultiverseCore.utils.SimpleSafeTTeleporter.teleport(SimpleSafeTTeleporter.java:335) [Multiverse-Core-2.5-b717.jar:?]
        at com.onarandombox.MultiverseCore.commands.TeleportCommand.runCommand(TeleportCommand.java:163) [Multiverse-Core-2.5-b717.jar:?]
        at com.pneumaticraft.commandhandler.multiverse.CommandHandler.checkAndRunCommand(CommandHandler.java:279) [Multiverse-Core-2.5-b717.jar:?]
        at com.pneumaticraft.commandhandler.multiverse.CommandHandler.processFoundCommands(CommandHandler.java:143) [Multiverse-Core-2.5-b717.jar:?]
        at com.pneumaticraft.commandhandler.multiverse.CommandHandler.locateAndRunCommand(CommandHandler.java:93) [Multiverse-Core-2.5-b717.jar:?]
        at com.onarandombox.MultiverseCore.MultiverseCore.onCommand(MultiverseCore.java:906) [Multiverse-Core-2.5-b717.jar:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1162) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:997) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_91]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_91]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_91]
Caused by: java.lang.NullPointerException
        at com.koens.perworldwelcome.listeners.WorldChangeListener.setupJoiningWorldList(WorldChangeListener.java:167) ~[?:?]
        at com.koens.perworldwelcome.listeners.WorldChangeListener.onPlayerWorldChange(WorldChangeListener.java:80) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_91]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_91]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_91]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.8.8.jar:git-Spigot-e4d4710-e1ebe52]
        ... 29 more