Bukkit

What steps will reproduce the problem?
1. Install the plugin with Download link
2. Paste it in server/plugins
3. Running server, gets errors and plugin is not loaded properly

What is the expected output? What do you see instead?
The plugin is install correctly for most users, but insted I get this error: http://pastebin.com/U9kiSf4k (Relative part of log)

What version of the product are you using?
showcase-0.7.9 on bukkit dev

Do you have an error log of what happened?
Yep.

Please provide any additional information below.

I also use these plugins for my server:
WorldEdit Vault Multiverse (Core, portals, signportals, netherportals) bLift PermissionsEx SafeCreeper LWC WorldGuard TreasureHunt Timber TreasureChest ModifyWorld(Not activicated) MobDisguise mcMMO Smart Moving Essentials Citizens EssentialsProtect EssentialsSpawn VanishNoPacket EssentialsChat

I am interested to install Showcase plugin more than every plugin else, so if this issue is cause by an incompatible plugin, please reply with a detail of which plugin being incompatible and I may remove it.

Thank you for your trouble.
-Vincent