2013-02-09 20:37:10 [SEVERE] Could not pass event BlockBreakEvent to cRecipes v1.0.6-b30
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.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
	at net.minecraft.server.v1_4_R1.PlayerInteractManager.breakBlock(PlayerInteractManager.java:282)
	at net.minecraft.server.v1_4_R1.PlayerInteractManager.a(PlayerInteractManager.java:209)
	at net.minecraft.server.v1_4_R1.PlayerConnection.a(PlayerConnection.java:567)
	at net.minecraft.server.v1_4_R1.Packet14BlockDig.handle(SourceFile:46)
	at net.minecraft.server.v1_4_R1.NetworkManager.b(NetworkManager.java:290)
	at net.minecraft.server.v1_4_R1.PlayerConnection.d(PlayerConnection.java:113)
	at net.minecraft.server.v1_4_R1.ServerConnection.b(SourceFile:39)
	at net.minecraft.server.v1_4_R1.DedicatedServerConnection.b(SourceFile:30)
	at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:598)
	at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224)
	at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:494)
	at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:427)
	at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.IllegalArgumentException: Cannot drop AIR.
	at org.apache.commons.lang.Validate.isTrue(Validate.java:157)
	at org.bukkit.craftbukkit.v1_4_R1.CraftWorld.dropItem(CraftWorld.java:295)
	at org.bukkit.craftbukkit.v1_4_R1.CraftWorld.dropItemNaturally(CraftWorld.java:312)
	at net.catharos.recipes.cRecipes.e(cRecipes.java:108)
	at sun.reflect.GeneratedMethodAccessor424.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
	... 16 more