10:04:56 ERROR]: Could not pass event AsyncPlayerChatEvent to MassiveCore v2.8.6
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:484) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.PlayerConnection.chat(PlayerConnection.java:1084) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1022) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.PacketPlayInChat$1.run(PacketPlayInChat.java:39) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_91]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_91]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_91]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_91]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_91]
Caused by: java.lang.NullPointerException
        at com.massivecraft.massivecore.engine.EngineMassiveCoreVariable.variableBook(EngineMassiveCoreVariable.java:101) ~[?:?]
        at com.massivecraft.massivecore.engine.EngineMassiveCoreVariable.variable(EngineMassiveCoreVariable.java:71) ~[?:?]
        at com.massivecraft.massivecore.engine.EngineMassiveCoreVariable.variable(EngineMassiveCoreVariable.java:66) ~[?:?]
        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.jar:git-Spigot-db6de12-18fbb24]
        ... 11 more
[10:04:56 INFO]: EpicBuild630: hi