[22:11:27 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'bgui
' in plugin BendingGUI v1.1
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spi
got.jar:git-Spigot-c516478]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:18
1) ~[spigot.jar:git-Spigot-c516478]
        at org.bukkit.craftbukkit.v1_8_R1.CraftServer.dispatchCommand(CraftServe
r.java:643) ~[spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.PlayerConnection.handleCommand(PlayerCon
nection.java:1083) [spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.PlayerConnection.a(PlayerConnection.java
:918) [spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(PacketPlayInChat.java
:26) [spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(PacketPlayInChat.java
:53) [spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.PacketHandleTask.run(SourceFile:13) [spi
got.jar:git-Spigot-c516478]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [
?:1.7.0_71]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.7.0_71]
        at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:6
84) [spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:3
16) [spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:6
25) [spigot.jar:git-Spigot-c516478]
        at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java
:528) [spigot.jar:git-Spigot-c516478]
        at java.lang.Thread.run(Unknown Source) [?:1.7.0_71]
Caused by: java.lang.ArrayIndexOutOfBoundsException: 17
        at org.bukkit.craftbukkit.v1_8_R1.inventory.CraftInventoryCustom$Minecra
ftInventory.setItem(CraftInventoryCustom.java:105) ~[spigot.jar:git-Spigot-c5164
78]
        at org.bukkit.craftbukkit.v1_8_R1.inventory.CraftInventory.setItem(Craft
Inventory.java:81) ~[spigot.jar:git-Spigot-c516478]
        at me.bubbleguj.bendinggui.util.GuiManager.openMainGui(GuiManager.java:5
3) ~[?:?]
        at me.bubbleguj.bendinggui.commands.CommandBendingGui.onCommand(CommandB
endingGui.java:33) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spi
got.jar:git-Spigot-c516478]
        ... 14 more