2013-09-20 21:46:31 [SEVERE] Could not pass event PlayerInteractEvent to Shop v1.4
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427)
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
	at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30)
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:478)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:463)
	at org.bukkit.craftbukkit.v1_6_R3.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:207)
	at net.minecraft.server.v1_6_R3.PlayerInteractManager.dig(PlayerInteractManager.java:108)
	at net.minecraft.server.v1_6_R3.PlayerConnection.a(PlayerConnection.java:539)
	at net.minecraft.server.v1_6_R3.Packet14BlockDig.handle(SourceFile:46)
	at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:230)
	at net.minecraft.server.v1_6_R3.PlayerConnection.e(PlayerConnection.java:116)
	at net.minecraft.server.v1_6_R3.ServerConnection.b(SourceFile:37)
	at org.spigotmc.netty.NettyServerConnection.b(NettyServerConnection.java:132)
	at net.minecraft.server.v1_6_R3.MinecraftServer.t(MinecraftServer.java:594)
	at net.minecraft.server.v1_6_R3.DedicatedServer.t(DedicatedServer.java:240)
	at net.minecraft.server.v1_6_R3.MinecraftServer.s(MinecraftServer.java:483)
	at net.minecraft.server.v1_6_R3.MinecraftServer.run(MinecraftServer.java:415)
	at net.minecraft.server.v1_6_R3.ThreadServerApplication.run(SourceFile:583)
Caused by: java.lang.NoClassDefFoundError: org/bukkit/craftbukkit/v1_6_R2/inventory/CraftItemStack
	at com.snowgears.shop.DisplayItem.spawn(DisplayItem.java:71)
	at com.snowgears.shop.DisplayItem.<init>(DisplayItem.java:42)
	at com.snowgears.shop.ShopObject.<init>(ShopObject.java:53)
	at com.snowgears.shop.ShopListener.onBlockClick(ShopListener.java:317)
	at sun.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
	... 17 more
Caused by: java.lang.ClassNotFoundException: org.bukkit.craftbukkit.v1_6_R2.inventory.CraftItemStack
	at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:70)
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 25 more