[21:27:47] [Server thread/ERROR]: Could not pass event InventoryClickEvent to RealisticBackpacks v1.6
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427) ~[craftbukkit_dev_2887.jar:git-Spigot-1171]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit_dev_2887.jar:git-Spigot-1171]
	at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30) ~[craftbukkit_dev_2887.jar:git-Spigot-1171]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:478) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:463) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:1360) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.PacketPlayInWindowClick.a(SourceFile:32) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.PacketPlayInWindowClick.handle(SourceFile:10) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:647) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:259) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:530) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:442) [craftbukkit_dev_2887.jar:git-Spigot-1171]
	at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit_dev_2887.jar:git-Spigot-1171]
Caused by: java.lang.NumberFormatException: For input string: "BP"
	at java.lang.NumberFormatException.forInputString(Unknown Source) ~[?:1.7.0_21]
	at java.lang.Integer.parseInt(Unknown Source) ~[?:1.7.0_21]
	at java.lang.Integer.parseInt(Unknown Source) ~[?:1.7.0_21]
	at org.fatecrafters.plugins.util.RBUtil.getItemstackFromString(RBUtil.java:71) ~[?:?]
	at org.fatecrafters.plugins.util.RBUtil.itemsAreEqual(RBUtil.java:122) ~[?:?]
	at org.fatecrafters.plugins.listeners.InventoryListener.onInventoryClick(InventoryListener.java:144) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor140.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_21]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_21]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425) ~[craftbukkit_dev_2887.jar:git-Spigot-1171]
	... 14 more