[20:18:36] [Server thread/ERROR]: Could not pass event EntityToggleGlideEvent to CDGS_Elytras v1.0
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot.jar:git-Spigot-90839e6-c5d27c5]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-90839e6-c5d27c5]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at org.bukkit.craftbukkit.v1_9_R1.event.CraftEventFactory.callToggleGlideEvent(CraftEventFactory.java:1018) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.EntityPlayer.N(EntityPlayer.java:1173) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.PlayerConnection.a(PlayerConnection.java:1482) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.PacketPlayInEntityAction.a(SourceFile:43) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.PacketPlayInEntityAction.a(SourceFile:9) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [?:1.7.0_79]
	at java.util.concurrent.FutureTask.run(FutureTask.java:262) [?:1.7.0_79]
	at net.minecraft.server.v1_9_R1.SystemUtils.a(SourceFile:45) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.MinecraftServer.D(MinecraftServer.java:721) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.DedicatedServer.D(DedicatedServer.java:400) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.MinecraftServer.C(MinecraftServer.java:660) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at net.minecraft.server.v1_9_R1.MinecraftServer.run(MinecraftServer.java:559) [spigot.jar:git-Spigot-90839e6-c5d27c5]
	at java.lang.Thread.run(Thread.java:745) [?:1.7.0_79]
Caused by: java.lang.IllegalArgumentException: Item cannot be null
	at org.apache.commons.lang.Validate.noNullElements(Validate.java:364) ~[spigot.jar:git-Spigot-90839e6-c5d27c5]
	at org.bukkit.craftbukkit.v1_9_R1.inventory.CraftInventory.addItem(CraftInventory.java:274) ~[spigot.jar:git-Spigot-90839e6-c5d27c5]
	at zeedin.cdgs.Elytras.Main.onGlide(Main.java:69) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor116.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_79]
	at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_79]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot.jar:git-Spigot-90839e6-c5d27c5]
	... 17 more