The themes keep come out this error whats happen?

Can teach me how to solve it?

[11-Oct-2012 01:41:59] PHP Fatal error: Class ‘TB_ExtensionPlugin’ not found in /home/kenneth8/public_html/kenz.com.my/tb_themes/shoppica2/catalog/plugin/CommonPlugin.php on line 3 [11-Oct-2012 01:57:53] PHP Fatal error: Class ‘TB_ExtensionPlugin’ not found in /home/kenneth8/public_html/kenz.com.my/tb_themes/shoppica2/catalog/plugin/FooterInfoPlugin.php on line 3 PHP Fatal error: ‘The class cannot be found: Theme_Catalog_error_log’
in /home/kenneth8/public_html/kenz.com.my/tb_themes/shoppica2/library/ExtensionPluginBootstrap.php:152
Stack trace:
#0 tb_themes/shoppica2/library/ExtensionPluginBootstrap.php(104): TB_ExtensionPluginBootstrap->loadPlugins()
#1 tb_themes/shoppica2/catalog/ThemeCatalogExtension.php(20): TB_ExtensionPluginBootstrap->configureAll()
#2 tb_themes/shoppica2/library/CatalogManager.php(36): Theme_Catalog_Extension->configure()
#3 tb_themes/shoppica2/library/CatalogDispatcher.php(47): TB_CatalogManager->initExtensions(Object(TB_DataBag))
#4 catalog/controller/common/tb.php(35): TB_CatalogDispatcher->dispatch()
#5 [internal function]: ControllerCommonTb->index(Object(Front))
#6 system/engine/front.php(42): call_user_func_array(Array, Array)
#7 system/engine/front.php(29): Front->execute(Object(Action))
#8 index.php(219): Front->dispatch(Object(Action), Object(Action))
#9 {main}