[12:31:59 ERROR]: Could not pass event PlayerInteractEvent to Vouchers v1.6.1
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:310) ~[spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav
a:62) ~[spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j
ava:502) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j
ava:487) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at org.bukkit.craftbukkit.v1_8_R3.event.CraftEventFactory.callPlayerInte
ractEvent(CraftEventFactory.java:227) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at org.bukkit.craftbukkit.v1_8_R3.event.CraftEventFactory.callPlayerInte
ractEvent(CraftEventFactory.java:194) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at org.bukkit.craftbukkit.v1_8_R3.event.CraftEventFactory.callPlayerInte
ractEvent(CraftEventFactory.java:190) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java
:717) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.PacketPlayInBlockPlace.a(PacketPlayInBlo
ckPlace.java:52) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.PacketPlayInBlockPlace.a(PacketPlayInBlo
ckPlace.java:1) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:1
3) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [
?:1.8.0_121]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_121]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SystemUtils.java:19) [spig
ot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:7
14) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:3
74) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:6
53) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java
:556) [spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_121]
Caused by: java.lang.NullPointerException
        at me.BadBones69.Vouchers.controlers.VoucherClick.voucherClick(VoucherCl
ick.java:139) ~[?:?]
        at me.BadBones69.Vouchers.controlers.VoucherClick.onVoucherClick(Voucher
Click.java:75) ~[?:?]
        at sun.reflect.GeneratedMethodAccessor190.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1
.8.0_121]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_121]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:306) ~[spigot.jar:git-Spigot-f94fe8f-d27e6d0]
        ... 18 more