Your constructor of the main class is invalid i suppose. Did you not update ur plugin with the new version? Your constructor should be like this: Code: Public [pluginname] (PluginLoader pluginLoader, Server instance, PluginDescriptionFile desc, File folder, File plugin, ClassLoader cLoader) Your's is probably like this: Code: Public [pluginname] (PluginLoader pluginLoader, Server instance, PluginDescriptionFile desc, File plugin, ClassLoader cLoader) And remeber all classes with "ID" in their names are now "Id"