error

[13:50:02 WARN]:        at de.iraphi.rax.mines.PlayerMine$8.onInteract(PlayerMine.java:401)
[13:50:02 WARN]:        at de.iraphi.rax.menubuilder.inventory.InventoryMenuBuilder$1.interact(InventoryMenuBuilder.java:261)
[13:50:02 WARN]:        at de.iraphi.rax.menubuilder.inventory.InventoryListener.onInventoryClick(InventoryListener.java:114)
[13:50:02 WARN]:        at sun.reflect.GeneratedMethodAccessor325.invoke(Unknown Source)
[13:50:02 WARN]:        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[13:50:02 WARN]:        at java.lang.reflect.Method.invoke(Method.java:498)
[13:50:02 WARN]:        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:257)
[13:50:02 WARN]:        at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:78)
[13:50:02 WARN]:        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
[13:50:02 WARN]:        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:490)
[13:50:02 WARN]:        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:475)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:2112)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(PacketPlayInWindowClick.java:25)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(PacketPlayInWindowClick.java:1)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13)
[13:50:02 WARN]:        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[13:50:02 WARN]:        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:767)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:378)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:706)
[13:50:02 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:609)
[13:50:02 WARN]:        at java.lang.Thread.run(Thread.java:748)
[13:50:02 WARN]: Caused by: java.lang.NullPointerException
[13:50:02 WARN]:        at de.iraphi.rax.mines.Mine.<init>(Mine.java:46)
[13:50:02 WARN]:        at de.iraphi.rax.mines.PlayerMine.<init>(PlayerMine.java:78)
[13:50:02 WARN]:        at de.iraphi.rax.commands.player.mines.CMD_mine.onCommand(CMD_mine.java:182)
[13:50:02 WARN]:        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45)
[13:50:02 WARN]:        ... 26 more