[18:55:56 ERROR]: Could not pass event InventoryClickEvent to Plugin v8.7.7
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:514) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:499) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java:1484) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.PacketPlayInWindowClick.a(PacketPlayInWindowClick.java:15) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.PacketPlayInWindowClick.handle(PacketPlayInWindowClick.java:65) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:186) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java:81) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:734) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:275) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:584) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:490) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
Caused by: java.lang.ArrayIndexOutOfBoundsException: -999
        at org.bukkit.craftbukkit.v1_7_R4.inventory.MinecraftInventory.getItem(MinecraftInventory.java:60) ~[spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        at minecraftevi.core.shop.page.ShopPageBase.playerClicked(ShopPageBase.java:130) ~[?:?]
        at minecraftevi.core.shop.ShopBase.onInventoryClick(ShopBase.java:144) ~[?:?]
        at sun.reflect.GeneratedMethodAccessor208.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_131]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_131]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:298) ~[spigot.jar:git-Spigot-1.7.9-R0.2-205-gb748d57]
        ... 13 more