stack trace zombies

[18:02:07] [Server thread/INFO]: [Zombies] Enabling Zombies v1.5.0
[18:02:07] [Server thread/INFO]: [Zombies] Succesfully loaded explosives.yml
[18:02:07] [Server thread/INFO]: [Zombies] Succesfully loaded guns.yml
[18:02:07] [Server thread/INFO]: [Zombies] Succesfully loaded knives.yml
[18:02:07] [Server thread/INFO]: [Zombies] Loading in games and arenas...
[18:02:07] [Server thread/INFO]: [Zombies] Adding arena night to game 1
[18:02:07] [Server thread/INFO]: [Zombies]  - Adding section Main
[18:02:07] [Server thread/INFO]: [Zombies]   - 2 item chests added
[18:02:07] [Server thread/INFO]: [Zombies]   - 5 monster spawns added
[18:02:07] [Server thread/INFO]: [Zombies]  - Adding section 1
[18:02:07] [Server thread/INFO]: [Zombies]   - 1 doors added
[18:02:07] [Server thread/INFO]: [Zombies]   - 3 monster spawns added
[18:02:07] [Server thread/INFO]: [Zombies]   - 1 mystery box added
[18:02:07] [Server thread/INFO]: [Zombies]   - 1 power switch added
[18:02:07] [Server thread/INFO]: [Zombies]  - Adding section Power
[18:02:07] [Server thread/INFO]: [Zombies]  - Adding section 2
[18:02:07] [Server thread/INFO]: [Zombies]   - 1 doors added
[18:02:07] [Server thread/INFO]: [Zombies]   - 2 item chests added
[18:02:07] [Server thread/INFO]: [Zombies]   - 3 monster spawns added
[18:02:07] [Server thread/INFO]: [Zombies]   - 1 perk machines added
[18:02:07] [Server thread/INFO]: [Zombies]  - Adding section 3
[18:02:07] [Server thread/INFO]: [Zombies]   - 2 doors added
[18:02:07] [Server thread/INFO]: [Zombies]   - 2 item chests added
[18:02:07] [Server thread/INFO]: [Zombies]   - 1 monster spawns added
[18:02:07] [Server thread/INFO]: [Zombies]   - 3 perk machines added
[18:02:07] [Server thread/INFO]: [Zombies] Succesfully added arena night to game 1
[18:02:07] [Server thread/WARN]: [Zombies] No join sign was found for game 1
[18:02:07] [Server thread/INFO]: [Zombies] Loaded 1 game(s) from the cache
[18:02:07] [Server thread/ERROR]: Error occurred while enabling Zombies v1.5.0 (Is it up to date?)
java.lang.NullPointerException
	at com.matsg.zombies.command.SubCommand.<init>(SubCommand.java:13) ~[?:?]
	at com.matsg.zombies.command.SetPowerSwitch.<init>(SetPowerSwitch.java:23) ~[?:?]
	at com.matsg.zombies.command.MainCommand.<init>(MainCommand.java:30) ~[?:?]
	at com.matsg.zombies.Zombies.onEnable(Zombies.java:26) ~[?:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:271) ~[Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugin(CraftServer.java:376) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugins(CraftServer.java:326) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at net.minecraft.server.v1_11_R1.MinecraftServer.t(MinecraftServer.java:421) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at net.minecraft.server.v1_11_R1.MinecraftServer.l(MinecraftServer.java:382) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at net.minecraft.server.v1_11_R1.MinecraftServer.a(MinecraftServer.java:337) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at net.minecraft.server.v1_11_R1.DedicatedServer.init(DedicatedServer.java:272) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:544) [Spigot.jar:git-Spigot-3fb9445-6e3cec8]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]