[19:19:54] [Server thread/ERROR]: Could not pass event PlayerInteractEvent to Ships v5.1.0.0
org.bukkit.event.EventException: null
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:308) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:500) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:485) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at org.bukkit.craftbukkit.v1_13_R2.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:238) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.PlayerInteractManager.a(PlayerInteractManager.java:452) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:1240) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.PacketPlayInUseItem.a(PacketPlayInUseItem.java:37) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.PacketPlayInUseItem.a(PacketPlayInUseItem.java:1) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.a(SourceFile:10) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_181]
	at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_181]
	at net.minecraft.server.v1_13_R2.SystemUtils.a(SourceFile:199) [spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:896) [spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:411) [spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:831) [spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:729) [spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_181]
Caused by: java.lang.NullPointerException
	at java.util.HashSet.<init>(Unknown Source) ~[?:1.8.0_181]
	at org.ships.ship.type.types.Watership.getRequiredMaterials(Watership.java:172) ~[?:?]
	at org.ships.ship.type.types.Watership.checkRequirements(Watership.java:52) ~[?:?]
	at org.ships.ship.type.VesselType.attemptToMove(VesselType.java:69) ~[?:?]
	at org.ships.ship.AbstractShip.safeMove(AbstractShip.java:486) ~[?:?]
	at org.ships.ship.AbstractShip.moveTowards(AbstractShip.java:274) ~[?:?]
	at org.ships.ship.Ship.moveTowards(Ship.java:189) ~[?:?]
	at org.ships.event.commands.BukkitListeners.signClick(BukkitListeners.java:280) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor13.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_181]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_181]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:304) ~[spigot-1.13.1.jar:git-Spigot-2440e18-4228a56]
	... 17 more