Error

        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_131]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [spigot-1.8
.8.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:7
15) [spigot-1.8.8.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:3
74) [spigot-1.8.8.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:6
54) [spigot-1.8.8.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java
:557) [spigot-1.8.8.jar:git-Spigot-db6de12-18fbb24]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_131]
Caused by: java.lang.NullPointerException
        at Events.WearEvents.onInvClick(WearEvents.java:75) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0
_131]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0
_131]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1
.8.0_131]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_131]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:306) ~[spigot-1.8.8.jar:git-Spigot-db6de12-18fbb24]
        ... 15 more