class is missing PreparedSQLStatement

Hi, I have problems starting my web-application build with RealStudio 2011.4.3
After I installed some new Plugins (and may be deleted some) the application asks me:
this class is missing one or more methods of an interface it implements
Interfaces: PreparedSQLStatement

What can I do?

Ok, I got it. Long ago I put in the plugins folder some plugins for other databases than RealSQLDatabase that I dont need anymore. I’ve deletes those plugins from the plugin folder and now my application works fine.
Thank you.