MethodNotFoundException

http://stackoverflow.com/questions/14096479/methodnotfoundexception-when-the-method-obviously-exists <----- StackOverflow Question
Source: https://github.com/macintosh264/XYZShop
Log:

20:15:43[INFO] macintosh264 issued server command:/sell hand 20:15:43 [INFO] [XYZShop] MacCommand sell executed 20:15:43 [SEVERE] null org.bukkit.command.CommandException: Unhandled exception executing command 'sell' in plugin XYZShop v0.1.3 at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186) at org.bukkit.craftbukkit.v1_4_6.CraftServer.dispatchCommand(CraftServer.java:510) at net.minecraft.server.v1_4_6.PlayerConnection.handleCommand(PlayerConnection.java:979) at net.minecraft.server.v1_4_6.PlayerConnection.chat(PlayerConnection.java:897) at net.minecraft.server.v1_4_6.PlayerConnection.a(PlayerConnection.java:852) at net.minecraft.server.v1_4_6.Packet3Chat.handle(Packet3Chat.java:44) at net.minecraft.server.v1_4_6.NetworkManager.b(NetworkManager.java:290) at net.minecraft.server.v1_4_6.PlayerConnection.d(PlayerConnection.java:112) at net.minecraft.server.v1_4_6.ServerConnection.b(SourceFile:39) at net.minecraft.server.v1_4_6.DedicatedServerConnection.b(SourceFile:30) at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:598) at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:224) at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:494) at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:427) at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:849) Caused by: java.lang.NoSuchMethodError: dev.xyzcraft.net.database.DatabaseHandler.getItem(IS)Ldev/xyzcraft/net/xyzshop/dataObject/MSItem; at dev.xyzcraft.net.xyzshop.commands.SellCommand.onCommand(SellCommand.java:63) at dev.xyzcraft.net.xyzshop.util.MacCommand.onCommand(MacCommand.java:44) at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)...15 more