> [14:55:41 ERROR]: Could not pass event InventoryClickEvent to MassiveCore v2.14.0
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[server.jar:git-TacoSpigot-aa1afff]
at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:78) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1744) [?:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [server.jar:git-TacoSpigot-aa1afff]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_212]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_212]
at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:773) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:386) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:712) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:615) [server.jar:git-TacoSpigot-aa1afff]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_212]
Caused by: java.lang.NullPointerException
at org.jdgames.mobextras.integration.EngineShopGUIPlus.getMaterialSellValue(EngineShopGUIPlus.java:47) ~[?:?]
at org.jdgames.mobextras.action.ActionCollectorSell.onClick(ActionCollectorSell.java:71) ~[?:?]
at com.massivecraft.massivecore.engine.EngineMassiveCoreChestGui.onClick(EngineMassiveCoreChestGui.java:83) ~[?:?]
at sun.reflect.GeneratedMethodAccessor459.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_212]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_212]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:300) ~[server.jar:git-TacoSpigot-aa1afff]
... 16 more