[22:36:00] [Server thread/ERROR]: Could not pass event SSPreTransactionEvent to SignShop v2.8.4Dev
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:47) ~[craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [craftbukkit.jar:git-Spigot-1423]
	at org.wargamer2010.signshop.SignShop.scheduleEvent(SignShop.java:218) [SignShop.jar:?]
	at org.wargamer2010.signshop.listeners.SignShopPlayerListener.onPlayerInteract(SignShopPlayerListener.java:261) [SignShop.jar:?]
	at sun.reflect.GeneratedMethodAccessor109.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_25]
	at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_25]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) [craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:47) [craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [craftbukkit.jar:git-Spigot-1423]
	at org.bukkit.craftbukkit.v1_7_R3.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:212) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.PlayerInteractManager.dig(PlayerInteractManager.java:103) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:549) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.PacketPlayInBlockDig.a(SourceFile:53) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.PacketPlayInBlockDig.handle(SourceFile:8) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:167) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.ServerConnection.c(ServerConnection.java:77) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:713) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:283) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:576) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:482) [craftbukkit.jar:git-Spigot-1423]
	at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit.jar:git-Spigot-1423]
Caused by: java.lang.NullPointerException
	at org.wargamer2010.signshop.util.itemUtil.StackToMap(itemUtil.java:324) ~[?:?]
	at org.wargamer2010.signshop.util.itemUtil.filterStacks(itemUtil.java:380) ~[?:?]
	at org.wargamer2010.signshop.listeners.sslisteners.StockChecker.onSSPreTransactionEvent(StockChecker.java:31) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor420.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_25]
	at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_25]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[craftbukkit.jar:git-Spigot-1423]
	... 26 more