[17:59:37] [Server thread/ERROR]: Could not pass event InventoryClickEvent to HyperMerchant v1.57-dev
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:305) ~[spigot.jar:git-Spigot-952179b-e87122e]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-952179b-e87122e]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-952179b-e87122e]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-Spigot-952179b-e87122e]
	at net.minecraft.server.v1_8_R1.PlayerConnection.a(PlayerConnection.java:1588) [spigot.jar:git-Spigot-952179b-e87122e]
	at net.minecraft.server.v1_8_R1.PacketPlayInWindowClick.a(SourceFile:31) [spigot.jar:git-Spigot-952179b-e87122e]
	at net.minecraft.server.v1_8_R1.PacketPlayInWindowClick.a(SourceFile:9) [spigot.jar:git-Spigot-952179b-e87122e]
	at net.minecraft.server.v1_8_R1.PacketHandleTask.run(SourceFile:13) [spigot.jar:git-Spigot-952179b-e87122e]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [?:1.7.0_65]
	at java.util.concurrent.FutureTask.run(FutureTask.java:262) [?:1.7.0_65]
	at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:683) [spigot.jar:git-Spigot-952179b-e87122e]
	at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316) [spigot.jar:git-Spigot-952179b-e87122e]
	at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:623) [spigot.jar:git-Spigot-952179b-e87122e]
	at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:526) [spigot.jar:git-Spigot-952179b-e87122e]
	at java.lang.Thread.run(Thread.java:745) [?:1.7.0_65]
Caused by: java.lang.NullPointerException
	at grokswell.hypermerchant.ShopTransactions.Sell(ShopTransactions.java:76) ~[?:?]
	at grokswell.hypermerchant.ShopMenu.handleMenuItem(ShopMenu.java:504) ~[?:?]
	at grokswell.hypermerchant.ShopMenu.onInventoryClickOrCreative(ShopMenu.java:535) ~[?:?]
	at grokswell.hypermerchant.ShopMenu.onInventoryClick(ShopMenu.java:516) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor435.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_65]
	at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_65]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:301) ~[spigot.jar:git-Spigot-952179b-e87122e]
	... 14 more