Bukkit

What steps will reproduce the problem?
1. Open chest GUI of another plugin?
2.
3.

What is the expected output? What do you see instead?
No errors of course
Instead DungeonBridge enters errors into console with each "chest" inventory opened

What version of the product are you using?
B: DungeonBridge-2.3.jar for CB 1.7.2-R0.3

Do you have an error log of what happened?
[20:11:16] [Server thread/ERROR]: Could not pass event InventoryOpenEvent to DungeonBridge v2.3
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.craftbukkit.v1_7_R3.event.CraftEventFactory.callInventoryOpenEvent(CraftEventFactory.java:598) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.EntityPlayer.openContainer(EntityPlayer.java:627) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.craftbukkit.v1_7_R3.entity.CraftHumanEntity.openInventory(CraftHumanEntity.java:193) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.black_ixx.bossshop.core.BSShop.openInventory(BSShop.java:345) [BossShop.jar:?]
at org.black_ixx.bossshop.core.BSShops.openShop(BSShops.java:92) [BossShop.jar:?]
at org.black_ixx.bossshop.listeners.SignListener.interactSign(SignListener.java:110) [BossShop.jar:?]
at sun.reflect.GeneratedMethodAccessor192.invoke(Unknown Source) [?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) [?:1.7.0_45]
at java.lang.reflect.Method.invoke(Unknown Source) [?:1.7.0_45]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at org.bukkit.craftbukkit.v1_7_R3.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:216) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.PlayerInteractManager.interact(PlayerInteractManager.java:374) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:629) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.PacketPlayInBlockPlace.a(SourceFile:60) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.PacketPlayInBlockPlace.handle(SourceFile:9) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:157) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.ServerConnection.c(SourceFile:134) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:667) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:260) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:558) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
Caused by: java.lang.ClassCastException: org.black_ixx.bossshop.core.BSShopHolder cannot be cast to org.bukkit.block.BlockState
at ar.com.nicoit.DungeonBridge.DBOpenedInventoryListener.onInventoryOpened(DBOpenedInventoryListener.java:34) [?:?]
at sun.reflect.GeneratedMethodAccessor431.invoke(Unknown Source) [?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) [?:1.7.0_45]
at java.lang.reflect.Method.invoke(Unknown Source) [?:1.7.0_45]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) [craftbukkit-1.7.9dev.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]
... 28 more

Please provide any additional information below.
Version of Chest GUI plugin appearing to be "at fault" as well here..
BossShop - R: v2.1.0 for CB 1.7.9-R0.1